‘Signs of pure altruism converge in the brain and increase with age’, https://www.eurekalert.org/pub_releases/2016-08/uoo-sop081516.php, UNIVERSITY OF OREGON, EurekAlert! AAAS (15-AUG-2016).

The public good

People older than 45 receive more neural reward from seeing others better off, they give more money away and they score higher on pro-social personality traits than those under 45. (…) Since general benevolence increases with age (…) it suggests the possibility that life experiences may plant the seeds of pure altruism in people, allowing them to grow into the desire to contribute to the public good.