Get lots of love and nurturing.

Dr. Marian C. Diamond is one of the world’s foremost neuroanatomists.  She was conducting research with young rats to determine whether enriched conditions accelerated the growth of dendrites.   An enriched environment is one in which 12 rats are put together in a large cage filled with a variety of play objects.  In contrast, an impoverished environment houses one rat with no objects to play with.  The enriched rats ran maze tests faster than the impoverished ones, showing a greater ability to solve problems.

Dr. Diamond wanted to conduct the same experiment with older rats, and she chose 600 day-old rats, which is roughly the equivalent of a 60 year-old human.  However, several of the rats would die around the 600 day-old mark.  She decided to try and improve the rats’ longevity by adding an extra ingredient to the experiment: love.  Instead of putting the rats immediately in their control cages after they were cleaned, the scientists involved in the study held them against their lab coats and petted them.  The rats that were petted lived considerably longer than those that were not.