Parents who dismiss a toddler's foot-stomping and tantrum-throwing as ordinary growing pains may want to revisit that idea. Defiant, impulsive behaviour in preschool could hint that a child is at risk of developing a gambling problem later on in life.

At least that's the takeaway from a recent study published in Psychological Science linking "under-controlled" temperament in childhood to compulsive gambling.

If accurate, the report's authors say the findings could have far-reaching implications on the way we approach problems related to self-control and emotional regulation.

Researchers established the link by observing the behaviour of more than 1,000 toddlers from New Zealand and then following up with those individuals a few decades later.

Participants who were labelled as more restless, moody or inattentive than other three-year-old children were twice as likely to struggle with gambling at ages 21 and 32, the study found.

What's more is, researchers say they couldn't pin the disordered gambling on differences in intelligence, gender or family socioeconomic status, though all of these avenues were explored.

For David Hodgins, a psychologist who specializes in addictive behaviours, the study could help demystify the connection between impulsive gambling and the human brain.

"Studies like this help us clarify what the pathway is towards developing gambling and other addiction and mental health problems," said Hodgins, head of the University of Calgary's psychology department.

Up until now, Hodgins said the medical field's understanding of gambling issues and other addictions has been limited to studies of people who have already developed a problem.

All study subjects were born in the same birth cohort -- between April 1, 1972 and March 31, 1973 -- and were monitored by researchers as early as delivery. Investigators collected prenatal statistics on the individuals, and then followed up with the kids three years later.

At that point, the toddlers underwent a 90-minute assessment, which put their cognitive and motor skills to the test. An examiner then took note of each child's overall temperament, using what the study refers to as "a standardized behavioral-observation inventory."

Researchers used the results to sort the children into five temperament groups:

Under-controlled (10.4 per cent)



Inhibited (7.8 per cent)



Confident (27.5 per cent)



Reserved (14.8 per cent)



Well-adjusted (39.6 per cent)

Children in the "under-controlled" category were viewed by researchers as being willful, impulsive and overtly negative. Compared to their "well-adjusted" and even "reserved" counterparts, these toddlers were twice as likely to exhibit signs of disordered gambling in adulthood.

For those keeping score, girls were significantly outnumbered in the "under-controlled" category but overrepresented in the "inhibited" column, where subjects were labeled as fearful, shy and self-critical.

Nearly all of the study subjects had gambled when interviewed again at age 21, not a surprise if one takes into account the prevalence of scratch cards, casinos and games of chance. But 13 per cent of those respondents, mainly the "under-controlled" subjects, confessed to gambling in a disordered way.

These participants admitted to being preoccupied with betting, feeling a desire to wager again and again and even having gambling worm its way into their personal lives.

Psychiatrist Daniela Lobo stresses that the study isn't suggesting that all moody toddlers are on track to develop a gambling problem, but rather that testy children may be at a higher risk.

"Everybody who studies addictive behaviours we've always noticed that a number of our patients have high impulsivity," said Lobo, who works at the Centre for Addiction and Mental Health's Problem Gambling Service in Toronto.

"We've always questioned whether addiction was causing people to be more impulsive or whether those people were more impulsive to begin with."

Though the study has filled significant gaps, questions remain.

Lobo pointed out that temperament isn't a failproof sign that a child may develop a gambling problem. For instance, a person who is labelled as "impulsive" or a "risk taker" could easily funnel that energy into positive exploits such as entrepreneurship.

"If there's one thing we can take away, it's that addiction isn't a black-and-white issue," she said.

It's also worth noting that by age 32 only about four per cent of respondents still gambled in a disordered manner. Researchers also didn't have information on the behaviour of study participants in childhood and adolescence, with no explanation as to how a respondent's gambling habits evolved over time.

But psychologist Wendy Slutske, who conducted the study with three others, said the findings could still provide significant insight into whether individuals can prevent or regulate future problems.

"It fits into a larger story about how self-control in early childhood is related to important life outcomes in adulthood," Slutske said in a prepared statement.