Wondering what makes a child successful in life? Many often refer to the “Marshmallow Test” Developed by Walter Mischel at Stanford University in the late 1960s. The experiment tested young children’s ability to practice delayed gratification and later measured how that correlated with their success in life.
The study demonstrated that young children who were able to practice delayed gratification showed a higher level of success rates as it pertained to education, test scores and earnings. While the experiment showcased executive functioning at its finest, in subsequent years, researchers have worked to refine the results in the hopes of targeting the precise factors that may contribute to a child’s and, ultimately, an adult’s success.
New Study, Bigger Revelations
Recently, research was published in the Journal of the American Medical Association’s JAMA Psychiatry and breaks down components of success even further. The data came from the Quebec Longitudinal Study of Kindergarten Children with initial information collected by kindergarten teachers. A total of 2,850 participants were followed and their employment earnings were tracked from age 33 through 35.
Francis Vergunst, PhD, a leader of the study, felt trying to isolate the components of self-control would prove beneficial in aiding children that might be lacking in it.
“Self-control isn’t an easily defined concept. In the past, researchers have often combined multiple traits – such as the ability to pay attention, delay gratification, and regulate emotions – to create a single self-control variable,” Vergunst tells Parentology. “This makes it difficult to identify the ‘active ingredients’ that account for the association between childhood self-control and future life outcomes, which is an essential step if you want to design and test intervention programs.”
Attention & Self-Control Are Key

Vergunst and his colleagues found that the greatest single contributing factor to a child’s success is inattention. Both boys and girls that suffered from inattention, according to their kindergarten evaluation, typically earned less as adults. Conversely, children that exhibited prosocial behavior often earned more as adults.
Vergunst deems these findings significant as they isolate a specific area that can benefit from intervention. He also believes the ability to succinctly identify these traits at an early age is important. “We were interested in examining behaviors that are directly observable and can be measured based on a single assessment as early as possible i.e. when children enter school,” he says. “Hence the focus on a single time point in kindergarten.”
The study also allowed for different educational backgrounds. In earlier forms of “marshmallow testing,” it became clear children with higher IQs and parents with higher levels of education performed much better. Vergunst’s study adjusted for IQ and family adversity.
Aggressive Earnings?

While the ability to pay attention was the prominent factor for both boys and girls, boys had an additional indicator of poor success—aggression.
Boys that showed aggressive or opposition at their kindergarten evaluation also showed lower future earnings. Boys able to show kindness, helpfulness and consideration exhibited higher future earnings.
Vergunst finds this distinction interesting but says there needs to be more studies, “We don’t really know. Aggression might express itself differently in males and females at age 6 – perhaps it isn’t as readily observable in girls. But we don’t know.”
Vergunst plans further study on other contributing factors. “It would be interesting to test the moderating effects of the family environment – such as family structure or parental affection – on behaviors at age six. This is something we plan to do.”
For now, this research gives parents and teachers the ability to identify and intervene with children whose early childhood struggles may impact their adult lives.
What Makes a Child Successful in Life — Sources
Scientific American
JAMA Psychiatry
Arstechnica
Francis Vergunst, DPhil/Ph.D