The Brain Products Are Really Built For

Psychology fascinates me. A decent model of how the mind works helps when I am dealing with other people, but it is also useful for catching my own behaviours and idiosyncrasies. So when Product Faculty published their User Psychology Playbook for Product Managers, I read the whole thing. (For transparency: I took their Advanced Product Management course, paid for it with my own money, and I am a happy customer.)

Here is the bit that stuck: A product manager will tell you they design for the user. What they really design for is a much older machine -- the brain that protects your ego, remembers the start and the end of things, and reaches for the easy question whenever the honest one is too much work. Most good product design is just a polite accommodation of that wiring. Most manipulation is the same wiring, nudged one notch too far.

As far as the old brain's concerned, it's looking out for number one; it's all about you. Your old brain will ignore any messages that it sees as irrelevant.
-from User Psychology Playbook for Product Managers

In the age of social media and self-PR, it seems clear that people are only looking out for themselves. However, in our evolution-driven brain, the ego is certainly a priority but only insofar as making sure you survive long enough to pass on your DNA. In The Selfish Gene¹, Richard Dawkins lays out the science behind why parents will jump into burning buildings to save their children. Humans and our genetic cousins such as chimpanzees (99% shared DNA) and bananas (~50%) are vessels for our genes to continue replicating. Not only that, studies suggest that there are at least as many bacteria in the human body as there are cells of their host². Now, who is really in charge?

Another interesting aspect of our brain is our capacity for altruism. Jumping into the fire to save your child might make sense to ensure the survival of your DNA but what about the starving child across the globe? The Selfish Gene argues that this wiring evolved from tribal times where any person you meet was likely to share your genes and reciprocate acts of generosity. Altruism, in essence, is a by-product of our evolutionary origins.

That being said, Dawkins notes that understanding how the human brain is wired does not make acts of selfless bravery any less admirable or beautiful. The watchmaker who understands every component that goes into a watch can still marvel at their creation. In this case, our brains misfire in a way that is beneficial to humanity as a whole. In not so good cases, humans have been imbued with a capacity to rise above our genetic wirings but we often succumb to their whims.

This is the brain a product has to win over -- the one that screens out anything it decides is irrelevant to its own survival and standing. The playbook treats that as a targeting problem, where the job is to earn the old brain's attention. I read it as a responsibility problem. Designing around someone's self-interest is fair game, and honestly unavoidable. The question I keep coming back to is whether you are serving the person who carries that brain around, or just farming the parts of them that do not know they are being played.

When given a long list of items to remember, people are more likely to remember the first item (the primacy effect) and the last item (the recency effect).

Primacy and recency effects have been well established in recall of lists. However, I would argue that one's opinion of a product is not a test of recalling a list of features but your experience of using these features. Garbinsky (2014)³ found that in a hedonic situation involving gluttony (chips - my worst enemy, only rivalled by ice cream), people tended to remember the end better than the first due to an effect called memory interference. For example, multilingual people experience situations where you cannot recall a word that you know in another language. This effect also occurs in short-term memory. For this reason, recency effect has a stronger impact than primacy effect.

In 1993, Kahneman et al.⁴ found that test subjects preferred to submerge their hand in 14 °C water for 60 seconds with the temperature gradually raised to 15 °C compared to 30 seconds at 14 °C water. Clearly, the cumulative discomfort experienced over 60 seconds is greater than 30 seconds but duration does not seem to be a big factor compared to how the experience ended. The preference for ending at 15 °C over 14 °C is the recency effect in the quote above. I once self-administered the cold pressor test (a fancy name for dunking one's hand in ice water) with water temperature at 4 °C and held for the maximum of 4 minutes as per MacLachlan et al. 2016⁵. I suspect my unusually fond recollection of that event is partially attributable to the fact that the water temperature rose by roughly 1 °C over the duration of the test.

Finally, Varey & Kahneman (1992)⁶ experimentally demonstrated retrospective evaluations of films being well-predicted by a weighted average of the peak and final evaluations. This effect has been confirmed by another study (Redelmier & Kahneman, 1996)⁷ involving colonoscopy patients. More recently, a study (Do, et al., 2008)⁸ applied this theory to the evaluation of material goods and found similar results. For a product to be remembered positively, focus on the peak and final experiences. That being said, for itemized segments within the product like SKU recommendations, the primacy effect can come into play.

Stated as a tactic, that is harmless enough. Taken to heart, it is a quiet licence to engineer the memory instead of the experience. Stage one bright peak, stick the landing, and someone walks away remembering your product as better than the average minute of using it ever was. I have done a version of this to myself -- I remember that 4 °C ice bath fondly, and I am fairly sure the only reason is that the water crept up a degree before I pulled my hand out. The same trick can paper over a mediocre core, or send someone off feeling good about a decision that was bad for them. Craft or manipulation? It comes down to one question -- was the peak real, or just well-placed?

What numbers can you use to back up your claims? Amazon [...] know[s] that if we can see lots of other people have enjoyed a product, we'll be more likely to purchase it too.

When making decisions on purchases, humans do not evaluate a product or service holistically but substitute this cognitively intensive task with an easier one. Kahneman discussed this substitution bias in his book Thinking, Fast and Slow⁹. A sports car offers horse power, torque, 50-50 weight distribution, and a quick 0-60 time as substitute questions for the more difficult question of whether or not the car is right for you.

In his book, Kahneman gave an example of a stock trader who purchased Ford stocks because he liked their cars. Unfortunately, how much one likes a car is not the same question as how well-priced the company stock is. For what is often people's second biggest single-item expense, car purchases tend to be laden with emotion.

Social proof runs on the same shortcut. "Look how many people bought this" quietly answers the easy question -- do other people approve? -- and stands in for the hard one you actually care about, which is whether the thing is right for you. That swap is the exact gap that fake reviews, padded star ratings, and "only 2 left in stock!" wedge themselves into. The mechanism itself is neutral. What is not neutral is the person who decides which question the screen nudges you toward, because they are also deciding whether the shortcut helps you or picks your pocket.

Tinder revolutionized online dating by reducing the emotional friction involved. Rather than having to pour their hearts out in a message to a stranger, only to be ignored or rejected, now people just had to swipe right

Tinder took the dating world by storm by reducing the emotional cost of potential rejections to a swipe-and-forget process. The matching process is also random to the user, akin to a slot machine. Minimal emotional cost and randomness of matching led to a $18.6 B market cap of Match Group, the parent company of Tinder and other major dating platforms. Ironically, the long-term and prevalent use of these dating apps can affect the matrimonial zeitgeist for the worse.

1.6 billion swipes a day world-wide turns dating into a numbers game. Pull the slot machine lever enough times, and you are mathematically guaranteed to hit the jackpot. However, there are some downsides to chronic gambling. Reduced emotional cost has the consequence of devaluing individual relationships where people run at the first sight of trouble, on to their next match. Over time, this can lead to a decline in successful long-term relationships.

A danger of building massively successful products is the unknown unknowns. Products that took advantage of the brain's neural circuitry is changing the circuitry itself. Unfortunately, companies driven by the profit motive are not necessarily looking out for their users' best interests. It is unlikely that companies like Facebook or Twitter had foreseen all the ways that their product would be used today. And even the parts that were predictable to them, users' interests were put on the back burner chasing OKR. It is in our best interests then, as users, to be informed and prioritize our well-being. Products have limitless potential to add value to a person's life but you should always be its master, not its slave.