Moms talk, daughters’ hormones listen

Now hear this: A mother’s encouraging words heard over the phone biologically aid her stressed-out daughter about as much as in-person comforting from mom and way more than receiving instant messages from her.

That’s consistent with the idea that people and many other animals have evolved to respond to caring, familiar voices with hormonal adjustments that prompt feelings of calm and closeness, say biological anthropologist Leslie Seltzer of the University of Wisconsin–Madison and her colleagues. Written exchanges such as instant messaging, texting and Facebook postings can’t apply biological balm to frazzled nerves, the researchers propose in a paper published online July 29 in Evolution and Human Behavior.

Seltzer’s group found that 7- to 12-year-old girls who talked to their mothers in person or over the phone after a stressful lab task displayed drops in levels of cortisol, a stress hormone, accompanied by the release of oxytocin, a hormone linked to love and trust between partners in good relationships. Girls who instant messaged with their mothers after the lab challenge showed no oxytocin response and their cortisol levels rose as high as those of girls who had no contact with their mothers.

“At least in our subjects, instant messaging falls short of the endocrine payoff of speech or physical contact with a loved one after a stressful event,” Seltzer says.

It makes sense that speech, with ancient evolutionary roots, can trigger biological markers of reassurance, comments psychologist Jeffry Simpson of the University of Minnesota in Minneapolis. Mothers may have expressed support better in speech than in writing, or the tone of their voices could have had a special impact on daughters, Simpson says.

Unfamiliarity with instant messaging, especially among mothers, may have undercut the ability of digital connections to alleviate daughters’ stress in the new study, suggests psychologist Sandra Calvert, director of Georgetown University’s Children’s Digital Media Center in Washington, D.C. Still, “mom’s voice is very important to all of us who are daughters,” Calvert says.

Seltzer’s team studied 68 girls who reported good relationships with their mothers. Each girl spoke about a preselected topic for five minutes and then tried to solve mental arithmetic problems for five minutes in front of two strangers who maintained neutral facial expressions. Youngsters said that these tasks caused them considerable stress. Researchers tracked cortisol in saliva samples and oxytocin in urine samples.

Afterward, girls were randomly assigned to talk with their mothers in person, over the phone, via instant messaging or not at all. Mothers were told to offer as much emotional support to their daughters as possible.

Although this study found no hormonal benefit for instant messaging between mothers and daughters, children may profit biologically when such messages come from peers, remarks psychologist Kaveri Subrahmanyam of California State University, Los Angeles. A 2009 study found that instant messaging with an unknown peer for 12 minutes eased the sting of rejection among teens excluded from a group game in the lab.