Principal investigator Pamela M. Cole of Pennsylvania State University and colleagues tracked 120 predominantly white children from families above poverty but below middle income from the time they were 18 months to 48 months.
Through home and laboratory visits, they measured children's language and ability to cope with tasks that might elicit frustration.
In one lab-based task, children were asked to wait 8 minutes before opening a gift while their mothers finished "work" -- answering questions. Children's anger and regulatory strategies were observed during the 8-minute wait.
Among the strategies the children used were seeking support -- "Mom, are you done yet?" or "I wonder what it is?" -- and distracting themselves from the gift by making up a story or counting aloud.
The study, published in the journal Child Development, found children who had better language skills as toddlers and whose language developed more quickly expressed less anger at age 4 than their peers whose toddler language skills weren't as advanced.