The fact that taller people also tend to be slightly smarter is due in roughly equal parts to two phenomenathe same genes affect both traits and taller people are more likely than average to mate with smarter people and vice versaaccording to a study led by the University of Colorado Boulder.
The study did not find that environmental factors contributed to the connection between being taller and being smarter, both traits that people tend to find attractive.
The modest correlation between height and IQ has been documented in multiple studies stretching back to the 1970s. But the reasons for the relationship between the two traits has not been well understood.
The technique developed by the researchers at CU-Boulder to tease out those reasons may open the door for scientists to better understand why other sexually selected traitscharacteristics that individuals find desirable in matestend to be linked. People who are attractive because of one trait tend to have other attractive traits as well.
"Not just in humans but also in animals, you see that traits that are sexually attractive tend to be correlated," said Matthew Keller, assistant professor of psychology and neuroscience at CU-Boulder and lead author of the study appearing in the journal PLOS Genetics. "So if you have animals that are high on one sexually selected trait they are often high on other ones, too. And the question has always been, 'What's the cause of that?' And it has always been very difficult to tease apart the two potential genetic reasons that those could be related."
The key to the technique developed by Keller, also a fellow at CU-Boulder's Institute for Behavioral Genetics, and his colleagues is using data collected about fraternal twins, identical twins and, importantly, their parents.
It has been common in the past to use information about identical twins and fraternal twins to determine whether a particular trait is inherit
|Contact: Matthew Keller|
University of Colorado at Boulder