Truth behind babies born in December as ‘smart months’ are explained

If you're a parent to an autumn baby, you'll know there's quite a hefty difference between their age when they begin school compared to summer babies in the same year group.

For example, a child starting school born in September - December will have just turned five compared to a child born in August - also in the same year group - who has only just turned four.

Over the years, there has been speculation about the intelligence of summer and autumn babies, and whether those born in the final months of the year have greater intelligence.

One study has shed some light on the debate. In 2023, research from Japan, published in Labour Economics, revealed that younger children in a given year group scored poorly in both academic tests and other life skills.

There can be a big age gap between babies born at the start of the school year, compared to the end (Getty Stock Photo)

The study explains: "Our estimation results indicate that the month of birth affects both cognitive and noncognitive skills.

"... The youngest students in grade four have test scores about 0.35 standard deviations lower than those of the oldest students; however, these gaps in test scores decrease to 0.13-0.18 by grade nine.

".... Consistent with existing psychological studies on adolescence, noncognitive skills tend to decrease with grade in our data. However, the youngest students in a given grade have noncognitive skills about 0.1 standard deviations lower than the oldest students in the same grade.

"Because noncognitive skills do not improve with grade, the gap between the oldest and youngest students in the same grade suggests that the month of birth influences the formation of noncognitive skills." the study further adds.

Researchers went on to explain that younger children in the year group ended up putting in 0.3 hours more work per week, as well as spending more hours reading.

One study revealed younger children scored poorly in academic tests as well as other life skills (Getty Stock Photo)

However, because of this, they spent less time on other creative extracurricular activities, as well as sports.

"The youngest students in the ninth grade work 0.3 more hours per week outside of school than the oldest students," the team further explained. "They also read for more hours and are more likely to attend a prep school.

"Overall, younger students and their parents make compensatory investment in cognitive skills; however, they spend 0.2 fewer hours per week on sports, arts, and music, which may lead to lower noncognitive skills, in light of the findings of psychological studies."

Despite the outcomes of the study, there is also previous research to suggest that younger summer babies scored higher in IQ tests and were more creative.

Harvard researchers suggested that younger children in the year group could also be more determined, independent and adaptable than their peers.