Gorillas in our midst

Imagine you’re a psychology researcher at Harvard. You’ve recruited 200 students to watch a 75-second video. It shows 6 people passing a basketball. You ask the students to count the number of passes. At the 45-second mark, a woman in a full-body gorilla suit walks across the scene for 5 seconds.


How many students do you think will notice the gorilla?


The answer is 50%. Half won’t notice at all.


Experiments like this reveal the brain’s limitations. Other examples:


Despite its limited performance, the brain is an energy hog. It is 2% of body weight, but consumes 20% of blood sugar. And it tires easily. For example, a study of judges found they approved 65% of parole requests right after eating a snack or lunch. But approvals declined to zero after a few hours.


A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away.

-Antoine de Saint Exupéry


Less is more

Reduce cognitive load. Simplify for others:


And simplify for yourself:


Many wealthy people are little more than the janitors of their possessions.

-Frank Lloyd Wright


The best way to choose what to keep and what to throw away is to take each item in one’s hand and ask: “Does this spark joy?” If it does, keep it. If not, dispose of it. This is not only the simplest but also the most accurate yardstick by which to judge.

-Marie Kondo


Simons DJ, Chabris CF. (1999). Gorillas in our midst: sustained inattentional blindness for dynamic events. Perception. 28(9): 1059–1074.


Zhang W, Luck SJ. (2008). Discrete fixed-resolution representations in visual working memory. Nature. 453(7192): 233–235.


Gobet F, Clarkson G. (2004). Chunks in expert memory: evidence for the magical number four…or is it two? Memory. 12(6): 732–747.


See JE et al. (1995). Meta-analysis of the sensitivity decrement in vigilance. Psychol Bull. 117(2): 230–249.


Caird JK et al. (2018). Does talking on a cell phone, with a passenger, or dialing affect driving performance? An updated systematic review and meta-analysis of experimental studies. Hum Factors. 60(1): 101–133.


Danziger S, Levav J, Avnaim-Pesso L. (2011). Extraneous factors in judicial decisions. Proc Natl Acad Sci USA. 108(17): 6889–6892.


Orquin JL, Kurzban R. (2016). A meta-analysis of blood glucose effects on human decision making. Psychol Bull. 142(5): 546–567.


Wardle-Pinkston S, Slavish DC, Taylor DJ. (2019). Insomnia and cognitive performance: A systematic review and meta-analysis. Sleep Med Rev. 48: 101205.


Mergenthaler P et al. (2013). Sugar for the brain: the role of glucose in physiological and pathological brain function. Trends Neurosci. 36(10): 587–597.


Xie H et al. (2017). The more total cognitive load is reduced by cues, the better retention and transfer of multimedia learning: A meta-analysis and two meta-regression analyses. PLoS One. 12(8): e0183884.


Chernev A, Böckenholt U, Goodman J. (2015). Choice overload: A conceptual review and meta‐analysis. Journal Consumer Psychology. 25(2): 333–358.

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