We all know how important it is to tell our kids we love them (or do we?). But how often do we actually show them? In a very cool study that was just published in the Proceedings of the National Academy of Science found that the children of nurturing, caring parents have larger hippocampi (hippocampus is the singular, but we all have two—one on each side of the brain) than kids whose parents are less nurturing and caring.

The hippocampus is a pretty big deal. Even though it’s only about the size of your pinky finger, it helps regulate how we deal with stress and is involved in forming and storing memories. Smaller hippocampi have been linked to depression, PTSD, Alzheimers, and a lot of mental disorders.

How did the researchers measure love? That’s always a hard thing to do, but in this case, they watched parents as they helped their children deal with mildly stressful situations, such has having to wait before opening up temptingly wrapped presents.

You can read the actual study here: http://www.pnas.org/content/109/8/2854.full.pdf+html?sid=e5855592-9df9-4e5c-a87f-03c78bf410e5