Patience is metabolic

How patient are you? Do you turn away from a shop if there is a queue more than five people long even if you really wanted what the shop had to offer? Are you able to stand with equanimity in the checkout line while the person in front of you regales the checkout operator with the hilarious antics of their dachshund as they search through their wallet for an elusive loyalty points card? Do you calmly endure the 25 minutes of muzak you have to listen to while you wait for your telecommunications customer service operator to pick up your call, or do you scream imprecations at the phone and threaten to flush it down it the toilet if you have to listen to another loop of that anodyne melody? However much you have of it personally, you can recognise that on occasion patience is necessary but while the capacity to delay gratification is strong in humans it is not so strong in other species. The reasons why this might be so have been examined in a new paper by a researcher from the University of Nebraska.

For the new report the researcher examined 13 primate species (including gorillas, chimpanzees, lemurs, marmosets, tamarins, and bonobos) for their capacity for what he called “intertemporal choice”, or what in common terms would be called the capacity to wait or to delay gratification.

For instance, one study involved animals being able to choose between eating two grapes on a tray immediately or getting six grapes on a tray if they waited. The “wait times” were gradually increased until the animal reached an “indifference point” where it would choose a smaller immediate reward. For instance, he found that a chimpanzee will wait more than two minutes to be able to eat six grapes whereas a black lemur would rather eat two grapes now than wait 15 seconds for a bigger serving.

Within humans it has been shown that higher IQ, academic success, and working memory capacity correlates with a greater capacity to delay gratification. However, combining his own experiments with a review of the available literature on the topic the researcher concluded that cognitive ability and social complexity did not correlate with a species’ ability to show patience. This was using relative brain size compared to body size as a measure of cognitive ability.

What the results did show is that species with larger body mass, larger brains, longer lives, and larger home ranges are more inclined to wait longer for a bigger reward. Chimpanzees weigh around 38 kilos, live 60 years and range around 56 square kilometres. Cotton-top tamarins weigh less than half a kilo, live 23 years, and have a home range of around 100 square metres. Where chimps will wait around two minutes for a larger reward the tamarin will wait eight seconds before going for the immediate smaller reward.

The researcher believes that his findings tell us that what determines the evolution of patience is metabolic rate. Smaller animals tend to have higher metabolic rates and the higher your metabolic rate the more regularly you need fuel to drive your metabolism. The faster you need it the less you are able to delay gratification. This applies to food and it may have shaped a species’ general capacity for patience as well although that remains to be clearly shown.

Are you a chimpanzee, a tamarin, or a lemur? Can you wait for your grapes or do want less grapes so long as you get them right now! What is your “indifference point” and does it alter in different circumstances? As you make your self-assessment and make future decisions just remember the old adage that, “lemurs rush in where chimps fear to tread”.