Being socially rejected massively reduces a person’s effective IQ, research finds.
People told, “you will end up alone in life” experienced drops in analytical reasoning skills of 30%.
Their IQs also dropped around 25%.
Not only does rejection lower IQ, it also makes people more aggressive, other studies have shown.
The results suggest that intelligence may have evolved primarily to facilitate social relations.
For the study, people took a personality test and some were then told (falsely) that it indicated they would end up alone in life.
Afterwards they were given an IQ test.
The study’s authors explain the results:
“In all three studies, people exhibited significant cognitive decrements after they were told that they were likely to end up alone in life.
Thus, the prospect of social exclusion reduced people’s capacity for intelligent thought.
Moreover, the decrements in intelligent performance qualified as large effects every time.”
The researchers think that people’s IQ drops because they are in distress:
“…we can best explain the pattern of cognitive decrements by proposing that social exclusion constitutes a threatening, aversive event but that people strive to suppress their emotional distress, and the resulting drain on their executive function impairs their controlled processes.”
In other words, being told they would end up alone made it harder for them to concentrate, because they were trying to suppress negative emotions.
There is an intimate link between intelligence and social relations, the authors write:
“Our results are more consistent with the view that[…]
intelligence evolved as a means to support and facilitate social relations rather than to compensate for the absence of their advantages.
Our findings could even be taken to suggest that people responded as if being excluded from social groups removed the need for intelligent thought.”
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The study was published in the Journal of Personality and Social Psychology (Baumeister et al., 2002).