Evolutionary psychologist Satoshi Kanazawa at the the London School of
Economics and Political Science correlated data on these behaviors with IQ
from a large national U.S. sample and found that, on average, people who
identified as liberal and atheist had higher IQs. This applied also to
sexual exclusivity in men, but not in women. The findings will be published
in the March 2010 issue of Social Psychology Quarterly.
The IQ differences, while statistically significant, are not stunning -- on
the order of 6 to 11 points -- and the data should not be used to stereotype
or make assumptions about people, experts say. But they show how certain
patterns of identifying with particular ideologies develop, and how some
people's behaviors come to be.
The reasoning is that sexual exclusivity in men, liberalism and atheism all
go against what would be expected given humans' evolutionary past. In other
words, none of these traits would have benefited our early human ancestors,
but higher intelligence may be associated with them.
"The adoption of some evolutionarily novel ideas makes some sense in terms
of moving the species forward," said George Washington University leadership
professor James Bailey, who was not involved in the study. "It also makes
perfect sense that more intelligent people -- people with, sort of, more
intellectual firepower -- are likely to be the ones to do that."
Bailey also said that these preferences may stem from a desire to show
superiority or elitism, which also has to do with IQ. In fact, aligning
oneself with "unconventional" philosophies such as liberalism or atheism may
be "ways to communicate to everyone that you're pretty smart," he said.
The study looked at a large sample from the National Longitudinal Study of
Adolescent Health (Add Health), which began with adolescents in grades 7-12
in the United States during the 1994-95 school year. The participants were
interviewed as 18- to 28-year-olds from 2001 to 2002. The study also looked
at the General Social Survey, another cross-national data collection source.
Kanazawa did not find that higher or lower intelligence predicted sexual
exclusivity in women. This makes sense, because having one partner has
always been advantageous to women, even thousands of years ago, meaning
exclusivity is not a "new" preference.
For men, on the other hand, sexual exclusivity goes against the grain
evolutionarily. With a goal of spreading genes, early men had multiple
mates. Since women had to spend nine months being pregnant, and additional
years caring for very young children, it made sense for them to want a
steady mate to provide them resources.
Religion, the current theory goes, did not help people survive or reproduce
necessarily, but goes along the lines of helping people to be paranoid,
Kanazawa said. Assuming that, for example, a noise in the distance is a
signal of a threat helped early humans to prepare in case of danger.
"It helps life to be paranoid, and because humans are paranoid, they become
more religious, and they see the hands of God everywhere," Kanazawa said.
Participants who said they were atheists had an average IQ of 103 in
adolescence, while adults who said they were religious averaged 97, the
study found. Atheism "allows someone to move forward and speculate on life
without any concern for the dogmatic structure of a religion," Bailey said.
"Historically, anything that's new and different can be seen as a threat in
terms of the religious beliefs; almost all religious systems are about
permanence," he noted.
The study takes the American view of liberal vs. conservative. It defines
"liberal" in terms of concern for genetically nonrelated people and support
for private resources that help those people. It does not look at other
factors that play into American political beliefs, such as abortion, gun
control and gay rights.
"Liberals are more likely to be concerned about total strangers;
conservatives are likely to be concerned with people they associate with,"
Given that human ancestors had a keen interest in the survival of their
offspring and nearest kin, the conservative approach -- looking out for the
people around you first -- fits with the evolutionary picture more than
liberalism, Kanazawa said. "It's unnatural for humans to be concerned about
total strangers." he said.
The study found that young adults who said they were "very conservative" had
an average adolescent IQ of 95, whereas those who said they were "very
liberal" averaged 106.
It also makes sense that "conservatism" as a worldview of keeping things
stable would be a safer approach than venturing toward the unfamiliar,
Neither Bailey nor Kanazawa identify themselves as liberal; Bailey is
conservative and Kanazawa is "a strong libertarian."
Vegetarianism, while not strongly associated with IQ in this study, has been
shown to be related to intelligence in previous research, Kanazawa said.
This also fits into Bailey's idea that unconventional preferences appeal to
people with higher intelligence, and can also be a means of showing
None of this means that the human species is evolving toward a future where
these traits are the default, Kanazawa said.
"More intelligent people don't have more children, so moving away from the
trajectory is not going to happen," he said.