Perceiving and believing but not knowing

Giraffes enjoy a wider perspective than most mammals, thanks to their long necks. We humans, too, enjoy richer perspectives because our bigger brains enable abstract reasoning.

Our brains combine the inputs from our senses to form our views about society, sex, life, the universe, economics, politics, friendship, justice and everything else.

Usually, our senses serve us well, but not always. Sometimes, they provide us imperfect information. As a result, the models and theories that our minds create of the world around us and of our place in it, deviate to a greater or lesser extent from reality. Unchecked confidence in our models can stretch the band with reality until it breaks and when this happens, we have a crisis and often not just one of confidence.

"Whatever I have accepted until now as most true has come to me through my senses," wrote Descartes in 1639. "But occasionally I have found that they have deceived me, and it is unwise to trust completely those who have deceived us even once."

Let's use vision, our strongest sense, to illustrate how our senses can in fact deceive us.

Most of us believe our eyes without question. Looking at the drawings below we are confident that the two tables have different shapes. A gambler would bet money on it -- and lose. Few of us would pull out a ruler to measure the tables. When we are confident of what we see we often feel no need to verify it.

Figure 1 Roger Shepard's table

The above picture tricks us into believing that the table on the left is longer and thinner than the table on the right. Only when we compare length and width using a tape measure, do we learn that our mental image is wrong.

Even after we learn that the two tables are in fact the same, the illusion persists. Bias can trump reason and misperceptions persist even when we know them to be wrong. Try if you like, but you will not be able to see the two tables as having the same length and width. The best you can do is to actively ignore your perception and trust what you know to be true because you have physically measured it. This requires mental exertion.

There are many ideas that we have come to accept as true knowledge, even though they are demonstrably false. For example a basketball coach directs players to pass the ball to a specific player because he perceives this player to have a "hot hand". Unfortunately his confidence in this imaginary rule induces him to choose a tactic that is detrimental to the team's interest.

Statistical analysis has proven that the perception of the "hot streak" (or hot hand) is a fiction of the mind (Gilovich and al. [1985]) and if the coach had studied the research then he would direct the team to do the opposite, i.e. to pass the ball to the lesser scoring players. Passing the ball to players with a lower scoring percentage would result in a higher total score because the lesser scoring players tend to increase their percentages whilst those starting on a high percentage tend to see them decrease.

But would the well-informed coach change his tactics?

Just like our perception of the table persists after we learn that it is wrong, a basketball coach may persist in perceiving a hot hand after he has learned that there is no such thing.

The two tables show that our perception, leading to a belief, can be wrong. It also shows that once we are aware of it being wrong, it doesn't change our perception. Our false perception remains.

Not only do wrong perceptions lead to false beliefs, factual knowledge may be powerless to change those false beliefs and misperceptions.

Editor for Wired magazine and author of books on creativity and decision making Jonah Lehrer comments: "Even though I know all about Tversky and Gilovich's research – and fully believe the data – I still perceive the hot hand."Just like you and I continue to perceive the tables as different.

Even when the scoring percentage of the "hot-hand" drops (as it will), 'hot players' score more than other players simply because they are presented with more opportunities than their teammates after their initial lucky sequence. After the game, confirmation-bias is likely to kick-in: attention is directed away from scoring percentages and towards the total number of baskets made. The hot-streak player still comes out on top, even though her percentage may be below average. Actually the confirmation bias had already kicked in when we first suspected seeing the hot hand because during the game we were ignoring the misses and focusing on the scores made by the 'hot-hand'. Who is going to criticize the top-scorer or the coach who made the decision to have 'assists' directed to the top-scorer?

Confronted with proof that the hot streak is an illusion, many reject the facts and persist in their superstition. Many coaches today still stand by the hot hand illusion. Red Auerbach, the legendary coach of the Celtics, simply ignored the findings: "So he makes a study, I couldn't care less."³

The illusion persists like the illusion of the table above, except that we have learned to dismiss our intuitive perception of the table. Dismissing intuitive perception, however, is the exception rather then the rule. With regards to our mental models, what we know is often sidelined in favour of intuition.

The persistent confidence in the hot streak is not confined to the basketball field:

- a sales-person who closes three deals in a row gets the better quality and larger quantity of prospects and is therefore more likely to win the top sales award and a self-perpetuating cycle is put into motion, resulting in hero sales-reps;

- a stock-trader who selected a sequence of winning stocks gets more money and more latitude to invest;

- a CEO who headed two successful companies is expected to turn around the next company she heads;

- punters in the casino often keep an eye out for a player on a hot streak and once identified, they put their money with this "hot player", ...

If we refuse to check our beliefs then we are more likely to go down the path of overconfident decision-making (but that is for another article).

I hope that you now are aware, like Descartes, that our senses cannot be trusted blindly (no pun intended) and that we'd be wise to verify what we hear, see, read, smell, feel and believe. We can do worse than to follow president Reagan's advise when he famously said "Trust but verify".