Norman was bothered by his analysis and tried to find examples that refuted this conclusion: he failed. Every radical innovation he investigated was done without design research, without careful analysis of a person’s or even a society’s needs.
— Norman D., Verganti R. (2012) Incremental and Radical innovation

The metaphor used in the paper is a common and very effective one: incremental innovation is like being on a mountain and trying to reach the top of it. Radical innovation instead is like jumping to a new mountain with the hope that it’s higher than the one you are on.

Understanding this is very important because it shows you the advantages and risks of both approaches. The incremental approach is very effective when grounded in research and is the one leading to the top, step by step. On the other side the radical approach isn’t usually grounded in research and has a quite high failure ratio because you can’t predict on which mountain you are going to land.

However, you can clearly see that:

Radical innovations seldom live up to their potential when first introduced. At first, they are often difficult to use, expensive, and limited in capability. Incremental innovation is necessary to transform the radical idea into a form that is acceptable to those beyond early adopters.
The bottom line is that both forms of innovation are necessary.

I think that you can see this clearly with startups. A startup by itself is usually an attempt in doing radical innovation, but in the principle it’s very very rough and requires lots of work to start growing and showing the full potential. Plus, if the idea isn’t delivering – the mountain isn’t as high as imagined – the startup usually pivots.

The paper goes on showing the two main dimensions where innovation can happen.

We conclude that human-centered design, with its emphasis on iterated observation, ideation, and testing is ideally suited for incremental innovation and unlikely to lead to radical innovation. Radical innovation comes from changes in either technology or meaning. Technology-driven innovation often comes from inventors and tinkerers. Meaning-driven innovation, however, has the potential to be driven through design research, but only if the research addresses  fundamental questions of new meanings and their interpretation.

And this is the most interesting part: technology and meaning, as two dimensions where innovation can happen. The two are related, and as such there’s always a bit of each in every innovation. The accent is where the main shift happens.

Let’s see briefly a few examples from the paper:

1. Market-Pull Innovation: any user centered design approach.
2. Technology-Push Innovation: the introduction of the color TV, the Xerox copier, the electronic calculator.
3. Meaning-Driven Innovation: the shift of watches from tools to fashion accessories, the invention of the mini-skirt in 1960s as a symbol of women’s freedom.
4. Technology Epiphanies: the Wii, using a new technology to change the space of video games.

Clearly, the Market-Pull Innovation is safer, while the Technology Epiphanies are way more difficult, also due to the resistance of the users to change.

You can find the full paper in PDF on this page. It’s worth a read. Norman and Verganti do a great work in detailing these two dimensions with some excellent examples and models.

“To some extent the social factors of status do affect how we perceive and value art, but what I want to try to convince you in this presentation is that there’s something else going on. Something that psychologists have called essentialism. And the idea of essentialism is that we don’t just focus on the superficial aspects of things, rather, we go deep. We are obsessed with origin and history. This is natural. Universal. Hard-wired and irresistible.”
— Paul Bloom

He does a lot of examples, spacing from art to sex and food as well, showing through these examples and researches how essentialism isn’t just a social and cultural construct, but exists in young children as well. Hard-wired indeed.

One of the examples he gives is an opera by Tom Friedman. The opera is a white piece of paper.  It’s a completely blank canvas. The title is “A thousand hours of staring”, and the reason of it is that the artist stared at that blank sheet of paper for 1.000 hours.

I think that essentialism points out a very interesting aspect that can give us a good way to interpret art and to juxtapose it to design. It will not answer every possible question, it won’t close any debate, but I still found it very interesting.

Follow me for a moment.

Essentialism might be the reason why design is different from art, even when the two result in exactly the same thing from a pure perception standpoint. Now of course it’s very difficult to have a work of art and a work of design producing exactly the same visual result, the same architecture, the same music or performance, or else, but it’s not hard to imagine if you take the example of Tom Friedman above, or if you remind the saying “Oh, I could have done that”.

The difference lies in what’s behind that. While both design and art can create beautiful results, it’s the essence of it, it’s the story behind that distinguish the two. In simplistic terms it’s also the amount of time that the opera symbolizes. It’s the meaning of it that’s important. It’s the human nature that it connects with, the one of the author(s) connecting in some way with yours.

That’s why two drawings that look exactly the same will be different when someone tells you that one is by Picasso and the other by their friend. It’s because we attach meaning to these art creation that transcend the appearance itself. I probably shouldn’t use this term, but in some way it is its “soul”.

That’s why if I take anything from the road and I place it inside an empty room in a museum, everybody will start thinking “what is the author trying to tell me?”. It’s automatic, because we expect that from art. And I’m not fantasizing: Marcel Duchamp did exactly this with his “Fountain“, and it’s also probably one of the provocations behind Piero Manzoni’s “Artist’s Shit“.

Essentialism doesn’t apply to art only, but from its perspective anything can be art as long as there’s a story attached to it with probably someone that injected a lot of thinking and made you think about your human nature.

So, what about design?

If we exclude the accepted fine arts and artistic disciplines like painting, writing, sculpting and so on, design is probably the non-artistic discipline more likely to be debated as art. The reason is simple: they are both creative processes and they both use the same media.

Using the essentialist perspective however you can see the difference between the two: art is defined by the author itself as a deep and meaningful process that, in the end, created the object or performance. Design instead doesn’t have this kind of story attached to the result itself. The essence of the two is deeply different, and as such, one is art and the other isn’t.

If you observe some edge cases you can see this. Take Philippe Starck lemon squeezer, the “Juicy Salif”. It’s a squeezer that doesn’t work. But Starck is a famous designer, he created it with a specific intent, it has a story attached, and it was built by a famous italian design brand, Alessi. Even the wikipedia entry of it tells the bit of story attached to it and quotes Starck saying “it’s not meant to squeeze lemons but to start conversations”. If you buy the Juicy Salif, it’s not to squeeze lemons. It’s for the story.
And it’s exposed at New York’s Museum of Modern Art.

I was discussing this perspective with photographer Claire Gaul and it came out that you can summarize and simplify it as: an object of design has its roots in what is going to do after it’s created, while an object of art has its roots in what happened before it was created. I must clarify immediately – thanks Riccardo - that this doesn’t imply that art “dies” once it’s done: both of them are going to be experienced in the future, you experience art after it’s done, it could make you cry and so on. But you can imagine like the weight exists in two different parts of the timeline.

The two things can be mixed, as in Starck’s example above.
The two things are also interwoven with a whole lot of other factors often debated when you try to define art.

In the end, essentialism alone isn’t able to define clearly the boundary of art and design, but I think that its perspective has a great value within this discussion. That’s why I encourage you to watch Paul Bloom’s “How Pleasure Work” and think about it.

A good leader has these four factors (Hogan, Kaiser, 2005):

1. Decisiveness: in case of uncertainity, they make decisions and take responsibility.
2. Competence: they are skilled and can create good teams.
3. Integrity: they are able to create deep trustworthy relationships.
4. Vision: they are able to see both short term and long term, seduce and inspire.

But to reach the next level and be a great leader, there are two more (Collins, 2001):

1. Modesty: it’s very interesting to see that modesty is a quality for great leaders, something that goes agains the common perception of being show-offs.
2. Persistency: they constantly push their goals, vision and push the team forward.

Jeremy wrote also another post, about the seven reasons why leaders fail. These are:

1. Strict hierarchies
2. Poor decision-making
3. Huge pay differentials
4. Impossible standards for leaders
5. Climb the greasy pole
6. Psychology of followership

These may all sound like pretty straightforward characteristics, but apparently few have what it takes. Many surveys have been carried out asking people what they think of their immediate bosses. On average these find that about half are seen as incompetent.
— Dean J. (2012) How to be a great leader

I did a quick summary here, but the two posts from Jeremy digs into much more detail: How to be a great leader and Seven reasons leaders fail.

I used to speak in a regular voice. I was able to assert, demand, question. Then I started teaching. At a university? And my students had this rising intonation thing? It was particularly noticeable on telephone messages. “Hello? Professor Gorman? This is Albert? From feature writing?” [...]

The sorority members’ own interpretation of uptalk was that it was a way of being inclusive. McLemore’s conclusions are somewhat similar. She says the rises are used to connect phrases, and to connect the speaker to the listener, as a means of “getting the other person involved.” [...]

Once commercial airline pilots start using uptalk, McLemore notes, it will mean that a full-blown dialect shift has occurred. Uptalk won’t be uptalk anymore. It will be, like, American English?
— James Gorman (1993) Like, Uptalk?

Here’s a video example of uptalk.

There are a lot of interesting details here. The first is that while it’s a simple and easy to spot inflection and as such it’s easy to notice its spread over different areas and countries, it’s still hard to track. It seems that it originated as a way of talking of the adolescent girls in California, and it inherited the name “Valley Girl” from a Frank Zappa song that highlights that intonation.

It’s even more interesting because while it’s commonly perceived as a adolescent, immature or low-class inflexion, some researches noticed some different scenarios:

McLemore studied intonation in one very particular context. She observed uses of intonation in a Texas sorority, where uptalk was not at all about uncertainty or deference. It was used most commonly by the leaders, the senior officers. Uptalk was a kind of accent, or tag, to highlight new information for listeners: “We’re having a bake sale? On the west mall? On Sunday?” When saying something like “Everyone should know that your dues should be in,” they used a falling intonation at the end of the sentence.
— Gorman James (1993) Like, Uptalk?

New studies show that people who use uptalk are not insecure wallflowers but powerful speakers who like getting their own way: teachers, talk-show hosts, politicians and facetious shop assistants.

Mark Liberman, a phonetician at the University of Pennsylvania, who has been monitoring George W. Bush’s speeches on his fascinating weblog Language Log, points out that the President has started peppering his Iraq speeches with HRTs. Why? Not, apparently, because Bush’s confidence is failing him. Rather, it has more to do with an aggressive need to direct conversation.
— Marsh Stefanie (2006) The rise of the interrogatory statement

That’s even more interesting, because if it’s validated as it seems happening, it might point out that adolescent girls are in fact the ones that are more able to evolve the language as a whole.

But linguists now say [...] Girls and women in their teens and 20s deserve credit for pioneering vocal trends and popular slang, they say, adding that young women use these embellishments in much more sophisticated ways than people tend to realize.
“A lot of these really flamboyant things you hear are cute, and girls are supposed to be cute,” said Penny Eckert, a professor of linguistics at Stanford University. “But they’re not just using them because they’re girls. They’re using them to achieve some kind of interactional and stylistic end.” [...]
Carmen Fought a professor of linguistics at Pitzer College in Claremont, Calif. ”The truth is this: Young women take linguistic features and use them as power tools for building relationships.”
— Quenqua Douglas (2012) They’re, Like, Way Ahead of the Linguistic Currrrve

This overall is an excellent example of spoken language evolution: its birth, usage, diffusion and perception. And also how we try to understand it and, sometimes, can’t just avoid it.

There are about 489,000 YouTube videos that say “no copyright intended” or some variation, and about 664,000 videos have a “copyright disclaimer” citing the fair use provision in Section 107 of the Copyright Act.
— Andy Baio (2011) No copyright intended

Finally, with mock exasperation, I said, “O.K., let’s try one that’s a little less complicated: You want a movie or an album. You don’t want to pay for it. So you download it.”

There it was: the bald-faced, worst-case example, without any nuance or mitigating factors whatsoever.

“Who thinks that might be wrong?”

Two hands out of 500.
— David Pogue (2007) The generational divide in copyright morality

These are excellent articles about a very interesting cultural shift: the perception of copyright. The problem here is that people have a natural inclination in sharing and manipulating and here they’re just doing that.

I’m not trying here to write extensively on copyright, but I’d like to point out some interesting details that sometimes are overlooked.

Copyright started as a protection for authors, and accordingly to Wikipedia it started with the printing press in 1662 first and 1709 next in England. There was no copyright before, because it was the printing press that made duplication easy. Copyright rises at the same time as a simple and cheap way of duplicating is born. This doesn’t mean that it didn’t exist before, the author always had rights, but copyright is explicitly tied with the problem of duplicating.

Today, copying is easy, and copyright is a very challenged law, not because there are people that like to pirate (even if, of course, there are) but because it harms not only them, but also the natural inclination of people of sharing and manipulating.

From a certain perspective, the kids that are posting these manipulated works are understanding copyright better than the people that made the law: they understand that the author must retain authorship and revenues and at the same time they can’t see a problem in sharing and manipulating.

The problem of duplications started only because at some point duplication become easier, simpler and cheaper, but payment to authors didn’t. Quite the opposite, from a certain perspective: paying an author in the 15th century meant just taking some coins and giving them to the author, today you have to pass through complex online payments systems, while copying is still just one click.

When you balance in these three factors:

1. natural inclination in sharing
2. simpleness and cheapness of copy
3. complexity of payment to authors

You see today’s copyright struggle clearly.

And you’ll see also another thing.

Today, you can change only one of these three variables. ;)

To me, claiming that Pictures Under Glass is the future of interaction is like claiming that black-and-white is the future of photography. It’s obviously a transitional technology. And the sooner we transition, the better.

With an entire body at your command, do you seriously think the Future Of Interaction should be a single finger?
— Bret Victor (2011) “A brief rant on the future of interaction”

I don’t think I have much more to add to this excellent article, even if unfortunately he’s downplaying a bit too much touch interfaces that are really here at consumer level since a few years ago.

To his point, I’d add that I don’t expect things like bendable devices, the kind of interactions that I expect in the future aren’t about making strange things to objects in order to perform arbitrary actions. If I pull something, I expect it to grow, or get longer, or open, not surely do some action on the screen.

As I often stated, the limit of today’s computing is in input-output, and even more in reality while we have lots of outputs (mouse, keyboard, touch, wiimote, camera, etc) we have very few inputs. When they ask me what screen I do want, I answer “I want as many pixel as possible”. The reason is simple: stand up now, make a few steps backward, and have a look the percentage of your field of vision that’s taken by the computer screen, compared to the whole space you’re in.

That’s why.

It’s tiny.

That’s also why another field I’m interested in is the internet of things: because it’s a way to make everything around you an input/output device that could interact with any part of your body… and maybe your mind as well.

Even if I was speaking mostly about design, I added some elements of business, strategy and change management as well, because I thought they were relevant.

I admit, this is a quite dense presentation, I would have probably taken out some topics in hindsight at least for UX Conference, trying to be more focused. However, on the plus side, from the feedback I got it was really successful and lots of people asked more. I probably need to do more workshop and less speeches in the future. :)

One method, two tools, three business tips. This is how I organized the presentation, in order to be not too unbalanced toward design, even if that was the focus, but also not being too high for more hands-on people.

One method

The most important part of Social Experience Design is that it can’t be done without a shift from traditional, deterministic thinking to the different Theory of Complexity thinking. This shift is critical because it’s the only way to deal with complex systems, such as people and social dynamics.

That’s why I talked again of the Dot Loop, because it contains all the factors that needs to be built-in in any design – well, in any company – to be really effective. The Dot Loop is an effective abstraction to deal with complex systems without a banalizing approach to them. Every successful company work that way – even, of course, probably they don’t call it Dot Loop, even if I’m starting hearing about it more often. :)

Two tools

The first tool is the Motivational Diamond, a very simple comparative visualizations that helps anyone working with social dynamics to focus on the four Relational Motivations (Competition, Excellence, Curiosity, Affection) and compare different services or parts of the service.

The second tool is the Social Usability and its Checklist, prepared to simplify the approach to it and provides an easy mnemonic. Social Usability works on four factors, that are Relations (the other), Identity (you), Communication (the channel between you and the other) and Emergence of Groups (all the emergent dynamics, again a complex system behavior).

Three business tips

These are very simple, but are also a very important part of a real change management process:

1. Be in-the-flow. This is critical in any good design tied to any change management process, but also for startups that are launching a new product: you have to understand that the day of your user is already
2. Be a double-pyramid business. This is a very important aspect, and might be an article by itself. Luckily it is: I wrote about the double-pyramid some time ago. This means that social businesses needs to engage in a different structure and find a balance between hierarchy and socialization, because the solution is in that balance and not in building a full hierarchic company or a full flat company.
3. Be a double double-pyramid business. Plus, you can’t be really a social business externally if you aren’t internally. You might have a unit that does customer service or social media operations, but if the whole company isn’t aligned, the users will get that, and the rewards are going to be lower (not zero, but lower).

The workshop

The extra part I prepared for Digital Accademia’s workshop regarded a couple of exercises to allow people focus a little more on how to use actively Relational Motivations and Social Usability.

I prepared two exercises to stimulate thinking and discussions:

• In pairs, draw a Motivational Diamond
  This is very interesting because it helps clarifying the four Relational Motivations by discussing it with a peer, and then the public discussions allow to clarify even more. As often happens in workshop, I learned something also this time: I have to clarify better that we are talking about traits that trigger relational aspects. For example, when we talk about “excellence” we aren’t talking about an excellent content, but about how we are promoting people’s excellence… and narcissism. :)
• In isolation, pick an item from the Social Usability Checklist and design an interface for it. Then, merge it with your partner to create a new UI with the two you prepared.
  I liked this one a lot because it shows how very simple solutions and interface can trigger more complex behaviours. One of the participants was worried because her solutions looked “too simple” but actually… that was the value of it! :)

A small joke

At UX Conference I was the last one of the day, so I had to think of something. That’s why I started with a small design practical joke… but I won’t tell what it was, and I removed it also from the presentation above. You’ll see the next time, maybe. ;)

“The best clients, to my mind, don’t say that whatever you do is fine, they’re intertwined in the process. When I look back, it’s hard to remember who had what thought when. That’s the best, most satisfying work, whether a large building or a house.”
— Peter Bohlin, Architect (2011) A Genius of the Storefront, Too

Peter Bohlin is the architect that worked with Steve Jobs to build the Apple Stores all around the world. The article by James Stewart is interesting, but for me that sentence above is the most interesting one.

When working together people are able to communicate better, avoid communication overhead and create consensus quickly. It’s obvious right? But so often within companies and teams this is taken as granted, and this happens both when there’s a positive outcome or a negative outcome.

When it’s positive, it just happened, so we usually don’t think that the project went smoothly thanks to this. When it’s negative, we just don’t think it was a problem of creating the environment for the team to communicate and collaborate effectively, because we expect that part should just happen. The justifications in the negative case are often external, we blame other things: we communicated badly, the specs weren’t clear enough, the client didn’t approve this in time, and so on. However, to a closer analysis, many times the issue was a team issue, missing a good and healthy collaboration space.

A few questions that could help you to see if you have a healthy team environment are:

1. Do I find effortless to communicate with others?
2. Am I able to get a clarification even for tiny doubts?
3. Do I chat even about non-related things with my team?
4. Am I isolating my work from others?
5. Do I know what each other is doing?

It’s even more interesting because if you think to the effectiveness of Agile, Lean and similar approaches from this perspective you notice that there are many techniques that in fact are just tricks to facilitate the communication and collaboration within the team. Why is the product owner included in the team itself? Why do daily stand-ups exist? Why are kanbans so effective?

Does your team has a healthy collaboration environment?
From this perspective, why do you think it works?

Debunking the bullshit

Do you remember in high school that poor kid that constantly had low grades in math but brush in hand will be able to blow your mind by drawing? And do you remember the kid that has excellent grades in math, but was incredibly awful in drawing anything, even just a straight line? And the other kid that looked all the time annoyed and had overall low grades, but everyone listened amazed at their stories? And that kid that everyone knew, that talked with everyone, all the time? Have you ever seen the difference between the kind of people that follow an Engineering class and an Art class? And between a nerd and a jock?

Do you know Howard Gardner? It was 1983 when he defined his Theory of Multiple Intelligences. He was able to define in a brilliant way that there are different kinds of intelligences, identified by their brain localization, their place in our evolution, the susceptibility to symbolic expression, a distinct developmental progression, the existence of savants and so on. The intelligences he found are:

• Spatial
• Linguistic
• Logical-Mathematical
• Bodily-kinesthetic
• Musical
• Interpersonal
• Intrapersonal
• Naturalistic

Then for the last 28 years, we read things like:

A designer who does not write markup and css is not designing for the web, but drawing pictures.
— Andy Rutledge (2011)

My short answer is “Learn code.”
— Frank Chimero (2011)

Honestly, I’m shocked that in 2010 I’m still coming across ‘web designers’ who can’t code their own designs. No excuse.
— Elliot Jay Stocks (2010)

Designers must have a solid working knowledge of at least one modern programming language (C or Pascal) in addition to exposure to a wide variety of languages and tools, including Forth and Lisp.
— Mitchell Kapor (1990)

Do you get what’s wrong here? Coding and Designing tap into two very different kinds of intelligence – it’s even more complicated than this, and Gartner is just a widely understood example, but let’s simplify for a second. We even have different stereotypes and jokes to identify the two categories lifestyles!

So, please stop: this recurring debate is harmful to both professions.

It’s harmful because since it tries to create hybrid professionals, that by themselves are good, but maybe there were just exceptional specialist professionals. Because it forces young designers to learn coding, when they should study for example cognitive psychology and social psychology. Because it slows down designers in becoming excellent in what they are paid for. Because it creates the expectations that “designers should code, so I don’t need a frontend developer” (harming also frontend developer specialization).

So, please: stop this bullshit.

The ratio

But wonder what? It’s more complicated than that. People that suggest that designers should be able to code are suggesting a solution to a problem they see, before analyzing the problem itself. Once we look at it, we notice that there are two components of the problem:

1. Know what code does
2. Know how to code

Knowing what is very different by knowing how. This takes us to the usual questions: do architects need to know how to build a skyscraper? Do car designers need to know how to build an engine? Do a movie director need to know how to act? Does a surgeon need to know how to build a pacemaker? Of course not.

But yes, they need to know what these things do. How they perform. What are their limits.

And yes, learning to write code is able to build both these knowledges.

But not both knowledges are required for designers and that’s why the whole “designers should code” is bullshit. The sentence should be: “designers must know the capabilities and limits of their media”.

And wonder what? That’s exactly what happens in other kinds of design! A print designer that has never seen a type foundry will still be able to create wonderful prints. An industrial designer that has never seen a lathe will still be able to create wonderful objects. It happens every day.

And here we’ll reach the second point: teamwork.

Because how should a designer learn the limits of his media? There are two ways: use it and collaborate with people that build it.

The digital team

Let’s see what happens in a near industry. Around 1960, William Bernbach had an interesting idea: instead of having art directors and copywriters in two different departments, with huge difficulties to communicate, let’s create creative teams: one art director and one copywriter together working on the same design at the same time. His company went from $1 million to $40 million thanks to his creativity and these structural changes. Today there are almost no agencies that split art directors and copywriters. They are teams.

In this digital world – no, I’m not just talking about the web – there is another kind of team, and if you have ever met a situation when this team was able to live you know how well it works. The team of the digital era is a designer / developer team — well, not exactly, but let’s stop here for now. Also, the missing copywriter here is a huge problem in my perspective, but I’ll talk about teams and creativity another time.

The reason is simple: in this way they talk and collaborate. They learn the limits of each other’s profession without knowing anything about how actually do it. Because it’s not a requirement for either of them. It’s more efficient, and well… it’s healthier as well to have someone to talk with and get a different perspective.

Is it all wrong then?

If you read so far you should know my answer. Yes: it’s more complicated than that. ;)

There’s still a good point in suggesting that designers should code (“Why, it isn’t possible to do that? I’ve seen it done by Facebook!” – argh it looks simple but it takes ages with this platform here!). Exactly as there’s a good point in suggesting that developers should learn some design basics (“Stop asking me to do it pixel perfect” – argh it’s not pixel perfect what I’m asking!).

The reasons are simple:

• It’s way easier to learn the basics of how to code than learning how to build a skyscraper.
• It’s one of the ways to balance over-specialization and be a better professional.
• In small teams or startups it surely makes the difference if you know both.

And the reverse is valid for developers too.

In any field, if you expand your view to know all the ecosystem around you it’s beneficial. You can’t know everything, because even in a single discipline there is enough knowledge to fill a couple of lifetimes, but knowing a little bit more helps a lot. And I’m not talking just about designers and developers, but all the things that happens in a project. Knowing about budgets, timeframes, clients, market, advertising, SEO, health, food… all things that are able to increase efficiency, satisfaction in the client and quality in the final product… and satisfaction for yourself as well.

So: you don’t have to learn a bit more outside your discipline, but you could.

However, please, please, please: before coding learn some cognitive and social psychology! It’s more important for your profession!

If you want to read more, there’s a great post from 2009 by Lukas Mathias about this same topic: “Designers are not Programmers” (I told you it’s an old and recurring topic), and thanks to Mark, Chris and Mike for the excellent discussions we had on this topic. Thanks also to Sean McCabe for a nice infographic to explain better the concept above about know what/know how.

Once understood the difference between “have to” and “could” the next step could be then a good explanation by Mike Rundle on the values of both generalists and specialist.

Q&A from the comments

• “HTML/CSS is not coding” or “Neither markup nor CSS are exceptionally difficult to learn” [1]
  I know that formally HTML/CSS are a different thing from a language like JavaScript, Ruby, Python or C++. But it is only in the eyes of someone that knows code already. It’s a distinction that goes missing to someone that doesn’t get it. Here, please, you have to understand that there are different people, with different mind, skills, and talents. Sure, there are designers that could code and aren’t doing that, but there are also designers that won’t be able to code at basic level in any way. There are people that can be wonderful specialists, and people that can be excellent generalists or T-shaped generalists. We are different, please, try to understand that before getting into a crusade.
  You might also want to have a read of this article by Jeff Atwood from 2006, describing a research paper about a test to separate programmers from non programmers: “Most people can’t learn to program: between 30% and 60% of every university computer science department’s intake fail the first programming course.”, or event better: “the act of programming seems literally unteachable to a sizable subset of incoming computer science students“. It’s a little superficial because the problem probably lies in the way the subject matter is taught, but it helps contextualize a bit this problem.
• “I think there is a semantic issue here on the definition of ‘designer’.”
  Yes. I kept the article vague, because that is a completely different argument, and I thought – but I might be wrong – that would have diluted the argument above. But YES, that’s another good point. There are very different kinds of design, but the overall criticism usually is triggered against any designer that works on the web, and that’s why I called bullshit. Working on the web doesn’t mean that you have to code, just that you could code, and that is valid if you are a “web designer” or “graphic designer” or “ux designer” or “ixd designer” that works on the web.
• “Gardner”
  A few people started arguing about the theory I cited. Yes, there are criticisms, but it’s not the point, it’s just a starting concept to frame a little better the article with the support of a quite widely known theory. As Domenico correctly suggested me, you can have a look at other researches as well, like the CHC Theory, the WAIS, the Hebbian theory or a more widely known author like Daniel Goleman. It surprised me that this was the central problem for a few people. :)
• “to really take art to the next level, you really have to learn to code.”
  Yes. To really take to the next level. Exactly like a painter can paint, but then can start creating his own paints, in every profession you can benefit for digging both deeper and wider in nearby fields. I can also argue that to take it really to the next level, you should learn cognitive psychology,  social psychology, gestalt theory, marketing, copywriting, information architecture, usability, economy, statistics, science of materials, architecture, and so on. Yes, all these things will benefit a designer. Actually, since we are talking about designers and not developers, I prefer to suggest first some of these other things than coding – some of them are HUGELY missing from design skillsets – but as you can see, there are lots of things that could take you to the next level. It just depends what next level are we talking about. The point of the article, however, isn’t that there are no “next levels”, is that you aren’t less of a designer if you can’t code. You are just choosing something else (hopefully!).
• “some example showing why designers should code”
  Most of the people that are using examples are showing problems in teamwork, collaboration and communication. It seems that lots of people think that by knowing better you’ll solve the problem of having “an arrogant designer telling you what to do”. Such a designer is bad, but if he learns coding it just get worse. Such a designer is bad because he doesn’t have the correct teamwork skills to cooperate properly, and the same problem could exists in the developer as well. So, improve teamwork skills before coding skills, and without such an ass in the team, the overall mood and productivity will increase for everyone. ;)
• “So, in the end, they should or shouldnt?”
  The summary, is that there’s no answer to this question. As I said repeatedly: it’s more complicated than that. The answer isn’t “yes” and isn’t “no”. The answer is “choose”.

Studer (1970, The Organization of Spatial Stimuli) discussed applying operant conditioning principles to the design of environments (such as buildings), by treating them as “learning systems arranged to bring about and maintain specified behavioral topographies…What operant findings suggest, among other things, is that events which have traditionally been regarded as the ends in the design process, e.g., pleasant, exciting, comfortable, the participant’s likes and dislikes, should be reclassified. They are not ends at all, but valuable means, which should be skillfully ordered to direct a more appropriate over-all behavioral texture.”
— Dan Lockton (2011) Design and behaviourism: a brief review

The whole article is a really interesting read for both designers and people involved daily in the creation of objects and spaces that are going to be used by people. So… I think pretty much anyone. :)

Another good part is at the beginning when he clears a common misconception between positive and negative reinforcements:

It is important to note here that in Skinner’s terms (1971, Beyond Freedom and Dignity), positive and negative reinforcement do not imply ‘good’ and ‘bad’, and negative reinforcement is a different concept to punishment. Positive reinforcement is giving a reward in return for particular behaviour; negative reinforcement is removing something unpleasant in return for particular behaviour.

There are a lot of interesting details like the two I cited above, but another summary that you can find in the text is about the different social trapscategories (Cross and Guyer, 1980):

1. Time-delay traps, where the lag between a behaviour and a reinforcer is too hight for it to be effective (“the high school dropout who, avoiding the present pain and unpleasantness of school, finds himself later lacking the education which could have prepared him for a more rewarding job”).
2. Ignorance traps, in which people fail to make use of generally available knowledge when making a decision.
3. Sliding reinforcer traps, in which certain behavioural patterns continue long after the circumstances under which that behaviour was appropriate, producing negative consequences
4. Externality traps, where the reinforcements relevant to the first individual may not coincide with the returns received by the second (“if you spend a lot of time choosing your dessert in the cafeteria, you will not suffer anything, but all the people behind you will”).
5. Collective traps, in which reinforcements or consequences will be paid by a group of people based on behaviour by one or more.

It’s interesting for me because as you can see all these categories are in a way or another a mismatch between the action and the received feedback, a mismatch that can be on different scales: type (positive good, positive bad), intensity (nothing, not enough), time (delay).

Take 10 minutes of your time and read the article, it’s worth it. :)

(thanks to Gianandrea for the tip)