Kendler et al. (2006) - Study | Psychology

IB Questions

• Genetics and Behaviour - Genes and Genetic Similarities

Name of the Researcher

Kendler

Publication

2006

Aim

To investigate to what extent major depressive disorder (MDD) is inherited.

Method

Correlation

Procedure and Participants

Participants - 15,000 Pairs of Twins

1. Participants were interviewed over a telephone.

2. The interview consisted of questions about lifetime prevalence of MDD using a DSM criteria and about their shared environment.

Results

The average heritability of MDD was 38%, however it was significantly higher in identical twins than fraternal twins and in women than men.

Strengths

+ Large Sample
+ Replication of twin studies have found similar results (35-45%)

Limitations

- Cause-and-Effect can’t be inferred.
- Difficulty Generalizing Findings to General Population