Genes may help determine how religious a person is, suggests a new study of US twins. And the effects of a religious upbringing may fade with time.
Until about 25 years ago, scientists assumed that religious behaviour was simply the product of a person's socialisation - or "nurture". But more
recent studies, including those on adult twins who were raised apart, suggest genes contribute about 40% of the variability in a person's
But it is not clear how that contribution changes with age. A few studies on children and teenagers - with biological or adoptive parents - show the
children tend to mirror the religious beliefs and behaviours of the parents with whom they live. That suggests genes play a small role in
religiousness at that age.
Now, researchers led by Laura Koenig, a psychology graduate student at the University of Minnesota in Minneapolis, US, have tried to tease apart how
the effects of nature and nurture vary with time. Their study suggests that as adolescents grow into adults, genetic factors become more important in
determining how religious a person is, while environmental factors wane.
The team gave questionnaires to 169 pairs of identical twins - 100% genetically identical - and 104 pairs of fraternal twins - 50% genetically
identical - born in Minnesota.
The twins, all male and in their early 30s, were asked how often they currently went to religious services, prayed, and discussed religious teachings.
This was compared with when they were growing up and living with their families. Then, each participant answered the same questions regarding their
mother, father, and their twin.
The twins believed that when they were younger, all of their family members - including themselves - shared similar religious behaviour. But in
adulthood, however, only the identical twins reported maintaining that similarity. In contrast, fraternal twins were about a third less similar than
they were as children.
"That would suggest genetic factors are becoming more important and growing up together less important," says team member Matt McGue, a psychologist
at the University of Minnesota. "
This is a really interesting study that brings up rather important questions. Are "athiest" and "secular" humanist genetically "deformed"? Are
the missing a gene due to evolution that makes them break their bond with the creator? Are they just a "mutation"?