As Jonathan and Matthew grow into adulthood, they are likely to use the same set of moral and ethical guidelines to choose their friends and select the groups they join. They will also be equally stubborn when they have to decide whether to comprise their values when it comes to new group memberships.
The same is not true of fraternal twins.
This is according to a new study by researchers at the University of Edinburgh, published in the November issue of the journal, Psychological Science. Unfortunately, there is a fee to view that article online and it's all written in complicated academic jargon anyway. A free and less technical summary was published this week in the online magazine, Science Daily.
The Edinburgh researchers assessed 1,000 pairs of adult twins, both identical and fraternal, to determine whether genetics plays a role in loyalty toward social groups and in how flexible people can be in adapting to group memberships.
The overwhelming finding was that it does affect both membership and flexibility.
Identical twins, who share DNA, functioned equally well or equally poorly in groups, and used the same ethical, religious and racial criteria to make their decisions. The same was not evident of fraternal twins, no matter how well-bonded they were.
Analysts seem to think the study will have military uses.
Already, I see that Matthew and Jonathan concur that Batman has a dark side and that the Teenage Mutant Ninja Turtles are cool. They also seem to be equally stubborn about which toys are worth fighting over and they both like preschool.
Surely the military can do something with that.