“Play with me, not with your cell phones,” read posters from a kids’ demonstration recently held by 7-year-old Emil Rustige in Germany’s Hamburg.

About 150 kids there protested their parents’ excessive use of mobile phones last week, and wondered what could be more compelling to parents than their own offspring.

Some days, just about anything is more compelling. But the mini-protesters have a point. And if kids in one part of the world are catching on that their parents are distracted by a phone obsession, it won’t be long before others elsewhere do, too.

It has been proven time and again that phone use gets in the way of personal interactions. Study upon study have found that the things we use devices for most (social media, games, even instant messaging) feed dopamine receptors in the brain in ways that mimic addiction. It’s difficult to put down the phone — especially if the alternative is to listen to a whining child.

But the fallout is well documented — above and beyond the anecdotal evidence of protesting German children. A study from the University of Michigan and Illinois State University found that low or seemingly normal amounts of tech-related interruptions were associated with more behavior problems in kids — oversensitivity, hot tempers, hyperactivity and whining. Children are resorting to problematic behavior, such as throwing tantrums or sulking, in order to get any attention, even if it’s negative attention, from adults busy with devices, concluded another study.

Various surveys have found kids beyond Emil are aware of competing with devices for their parents’ attention. For instance, one US survey found 33% of nearly 1,000 teens surveyed said they want parents to put down their phones during conversation. Another, larger-scale study, reported by The Swaddle, interviewed more than 6,000 children, aged 8 to 13, across eight countries — finding that more than half them felt their parents spent too much time on the phone. Further, one-third reported feeling neglected and unimportant when parents were preoccupied with their phones.

Catherine Steiner-Adair, a clinical and consulting psychologist at Harvard University, and author of The Big Disconnect: Protecting Childhood and Family Relationships in the Digital Age, interviewed more than 1,000 children between ages 4 to 18, and found across age groups, kids felt “exhausted and frustrated and sad or mad trying to get their parents’ attention, competing with computer screens or iPhone screens or any kind of technology,” according to this report by The Swaddle.

These studies highlighting the effect parents’ excessive use of mobile phones has on kids have been around for a while. But sometimes, you just need to hear something from the mouths of babes.