Study on Twins Shows that Experiences Help the Brain Grow

The adult brain continues to generate neurons as it seeks new experiences, a new study has found. This is the reason why identical twins living in the same environment develop strikingly different personalities even though they have the same set of genes.

The latest study on development of personality and behavior was conducted by researchers from Helmholtz Association of German Research Centres, who assessed the behavior of 40 sets of genetically identical mice raised in the same environment.

Each mouse in the experiment was fitted with a micro-chip that emitted electromagnetic signals. Researchers used these signals to track the movement of each mouse and constructed their personality profiles.

"The animals were not only genetically identical, they were also living in the same environment. However, this environment was so rich that each mouse gathered its own individual experiences in it. Over time, the animals therefore increasingly differed in their realm of experience and behavior," said Gerd Kempermann, Professor for Genomics of Regeneration, CRTD, and principal investigator of the study.

Researchers found that despite being raised in the same environment, each of the mice had a different personality and behavior patterns.

"Though the animals shared the same life space, they increasingly differed in their activity levels. These differences were associated with differences in the generation of new neurons in the hippocampus, a region of the brain that supports learning and memory," said Kempermann in a news release. "Animals that explored the environment to a greater degree also grew more new neurons than animals that were more passive."

Kempermann said that adult neurogeneration allowed mice to react to information from the environment with greater flexibility. He added that similar neurogeneration exists in humans as well.

The study offers evidence for the assumption that experiences are directly tied with the aging of the brain, said professor Ulman Lindenberger, Director of the Center for Lifespan Psychology at the Max Planck Institute for Human Development (MPIB).