Human Genome Project completed

The completion of the Human Genome Project launched the era of genetic research in psychology. Most mental disorders turned out to be polygenic.

The genetics of psychopathology has shown that most mental disorders are polygenic: influenced by hundreds or thousands of genetic variants, each with a small effect. This means there is no 'schizophrenia gene' or 'depression gene', but a complex mosaic of genetic influences interacting with the environment.

The first decade of the 21st century was a period of rapid advances in neuroscience, genetics, and behavioral economics. Functional neuroimaging allowed us to see the brain in action, while complete genomes opened the era of genetic research in psychology.

Significance: This milestone significantly contributed to the development of psychology as a science and profession, influencing research, clinical practice, or public policy.