A Great Tit Chick Hatches

Nov. 21, 2003 — DNA studies on the personality of birds, which researchers suggest could reflect on the behavior of humans and other animals, reveal that mates with opposing personalities produce offspring with higher survival rates.

The findings emerged from two papers released by biologists at the Netherlands Institute of Ecology (NIOO). The papers, recently presented at Utrecht University, contain the first personality research ever to illustrate genetic structure and its resulting effects on survival.

For the initial study, Kees van Oers used artificial selection to breed great tits (Parus major) with extreme personalities. Some of the birds were fast moving, aggressive risk takers. Others were more slow and cautious.

Care for Your Bird Bird Guide See Birds Live! Bird Feeder Cam Stories from the Past News Archives

Van Oers then analyzed the offspring of these two extremes. He discovered that the personalities of the offspring were 54 percent hereditary, with some genes for behavior dominating over others. This resulted in baby chicks with predictable, yet varying, personalities.

According to Froukje Rienks of NIOO, the other 46 percent of personality is caused by upbringing, events in life, and learning from chance happenings in the environment.

Both Rienks and van Oers told Animal Planet News that a similar mix of genetics and events produces personality in humans.

"Although the human personality structure is more sophisticated, the basics do apply," Rienks said.

For the second study, researchers Niels Dingemanse and Christiaan Both studied the survival rates for great tits in the wild. They discovered that "average types are the winners."

Couples with similar personalities tended to produce more extreme behaving offspring, meaning that the chicks were very fast and aggressive or very slow and cautious. Couples with opposing personalities did not have the happiest time together and produced smaller numbers of children, but they eventually wound up with more grandchildren due to less fluctuation in offspring survival rates.

Psychologist Samuel Gosling of the University of Texas at Austin agrees that such studies on birds can illuminate human behavior.

"With caution I think many of the findings from birds and animals can be applied to humans," Gosling said. "I anticipate that (van Oers') work will make especially large strides in examining the biological and genetic bases of personality. In turn this work will open the way for studies of more direct relevance to humans, such as examining the links between personality and health."

Van Oers and his colleagues plan to further study birds, this time concerning selection pressures due to climate change. Future studies on human personality also are in the works.

"The biggest advantage of using an animal as a model species for personality research is because a lot more is possible," explained van Oers, who will soon also be working for the Max-Planck Institute for Ornithology in Germany.

He added, "One major problem in human personality research is that the interaction between the genes and the environment an individual is living in is hard to study. In the future we will try to answer this question with the help of molecular markers."