"If it's a real, meaningful accomplishment it's not a bad thing to share that news with other people and for the child to celebrate that with their family members, perhaps with their friends," she says.
Parents today are more anxious about the economy and their children's futures than their predecessors, says University of Pennsylvania sociology professor Annette Lareau, and that can complicate the bragging versus sharing issue.
But she also points out that talking about your child's extracurriculars is an effective networking strategy.
"It takes a lot of informal knowledge to have your kids in organized activities," she says. You need to know about sign-up dates, carpool opportunities and how competitive, challenging or welcoming an activity will be.
"Mothers are very dependent on other mothers to share information," Lareau says.
Grolnick adds that there's even such a thing as sharing too little information about your child's triumphs.
"The problem comes in when you want to share something and you feel you shouldn't because that's going to be bragging, and you sit on it and don't get to have that connection with people."
If a parent can't stop telling you how great his or her kid is, try a little empathy, says Clark University psychology professor Wendy Grolnick. Ask yourself what this person might be going through emotionally that would explain the intense focus on her child's achievements, and remind yourself that nothing the other parent says has anything to do with you or your child.
A parent probably won't thank you for telling them to stop bragging, Grolnick notes, but you may want to consider limiting your exposure to repeat offenders:
"I always say, don't stand by the sidelines with a bragging person at the soccer game. Why do that to yourself?"