Birds' Personality a Result of Nurture Rather than Nature

A study on personality traits of zebra finches indicates that the birds' personality is a result of nurture, rather than nature.

To reach the conclusion, researchers at University of Exeter and the University of Hamburg tested the personality traits between generations of zebra finches reared with natural parents and with foster parents.

Environmental factors play a larger role than genetics, the researchers found, concluding that foster parents have a greater influence on the personalities of fostered offspring than the genes inherited from birth parents.

"This is one of the first experiments to show that behaviour can be non-genetically transmitted from parents to offspring. Our study shows that in zebra finches, personality traits can be transmitted from one generation to another through behaviour not just genetics." Nick Royle, a biologist at University of Exeter, said in a press statement.

To measure the personality, researchers placed zebra finches in a new environment and counted the number of visits the birds made to various features around the environment. Some were shy, staying mainly in one place while others explored widely, which the researchers report is demonstrative of a more outgoing personality.

Male and female birds were then paired up and allowed to breed. Each clutch of eggs was fostered by another pair just prior to hatching; the same test was performed to the fostered offspring once they were adults.

The researchers concluded that the way the finches were raised played more of a role in determining personality than their genetics.

Offspring size was also measured and was found to be primarily genetically inherited and not significantly influenced by foster parent size, the researchers reported.

The find prompts questions into the inheritance of personality in other species, including humans, including whether adoptive children inherit personality traits of their adoptive or birth parents.  

The researched is published in the journal Biology Letters.