Information VS impulse

Because working memory and rationality share a common cortical source; the pre-frontal cortex, a mind trying to remember lots of information is less able to exert control over its impulses.

I've been listening to an audible audio book called 'How We Decide'; It's full of gems like this. Stanford Scientists discovered the above fact by asking people to memorize 7 digits, under the guise of a 'long term memory test'. The subjects would then walk down the hall and choose between decadent chocolate cake or a bowl of fruit salad.

The same experiment was repeated, but with new subjects being asked to remember a 2 digit number. The difference was striking:

• 59% of people trying to remember the 7 digits chose the cake
• But only 37% of people trying to remember the 2 digits chose the cake

Distracting the brain with a memory task made people more likely to give-in to temptation and choose the calorie dense dessert.

The substrate of reason is so limited, that a few extra digits can become an extreme handicap.

I actually don't know how this relates to the 7 ± 2 that is oft-(over) quoted, but I've never heard about this impact on our ability to mediate our emotions.