Wired flags a new study that proves many mothers across the country right: For your own sake, you should call home more often. The research comes from Evolution and Human Behavior. It finds that a phone call to mom provides significant stress relief while instant message conversations won’t quell the nerves.

The conversations happened after research subjects took a stressful test. As subjects spoke (or typed) with their mothers, the researchers measured changes in levels of cortisol (generally linked to stress) and oxytocin (a hormone linked to pleasure). When subjects talked on the phone, cortisol levels dropped and oxytocin went up. But IMing with Mom looked the same as having no contact at all:

The study author tells Wired, “the results suggest that mom’s voice — its tones and intonations and rhythms, known formally as prosodics — trigger soothing effects, rather than what she specifically says.”

To summarize in non-chart form: Call your mother!