The "Golden Age" of Behavior Genetics?

Area of Science:

• Behavioral genetics
• Human genomics

Background:

• The heritability of human behavior is a complex trait.
• Early research focused on candidate-gene-association (CGA) studies, which are now largely disregarded.
• Current research employs genome-wide association studies (GWASs), single-nucleotide polymorphism (SNP) heritability estimates, and polygenic risk scores.

Purpose of the Study:

• To review the evolution of genetic research in behavior genetics.
• To analyze the persistent challenges and new difficulties in identifying genetic risk factors for complex human behaviors.

Main Methods:

• Review of historical and current methodologies in behavior genetics.
• Analysis of Fisher's "infinite infinitesimal allele" model in the context of postgenomics.

Main Results:

• Candidate-gene-association studies have been largely unsuccessful and are considered a "cautionary tale."
• Genome-wide association studies (GWASs) and related methods continue to face challenges.
• Underlying complexities of the human genome and limitations of existing models hinder progress.

Conclusions:

• Despite methodological shifts, identifying genetic risk factors for behavior remains challenging.
• Current approaches, while advanced, inherit limitations from earlier methods.
• Fisher's "infinite infinitesimal allele" model requires reevaluation in the postgenomics era.