Fatherly contact and child intelligence

“Children who spend large amounts of time with their fathers have higher IQs,” The Daily Telegraph reported. It said that, according to a new study, fatherly involvement in a child’s early life can also affect their career prospects. The Daily Mail also covered the story and said the study suggests that fathers who take a more active role have children that grow up to be more intelligent and climb higher up the social ladder.

This was a long-term study that followed 11,000 British men and women since their birth in 1958. While the study has some strengths in that it involved a large number of people over many years, it has several limitations. These mostly relate to how the information on fatherly involvement was initially collected, and certain measures that were not taken, such as independent measures of motherly involvement. The information on the father’s involvement was captured in 1969, and how applicable these findings are to today’s style of parenting is questionable. Intelligence is reliant on a variety of genetic and environmental factors.

Where did the story come from?

Daniel Nettle from the Centre for Behaviour and Evolution, Institute of Neuroscience at Newcastle University, carried out this research. No sources of funding were reported in the journal article. The study was published in the peer-reviewed medical journal, Evolution and Human Behaviour.

What kind of scientific study was this?

The author of this cohort study said that previous research has indicated that fathers become more involved with sons than with daughters, and that fathers in higher socioeconomic groups spend more time with their children than those of lower socioeconomic groups. The author wanted to investigate whether the amount of contact between father and child influences child outcomes. Specific attention was given to whether socioeconomic status and child gender influences fatherly involvement, and whether the level of involvement affects child IQ and social mobility. Possible reasons for this were explored.

The author used data from the National Child Development Study, an ongoing investigation of all 17,146 children born in the UK in a single week in March 1958 and their parents. The participants have received regular assessments over the past 50 years, most recently in 2004-5 at the age of 46. This particular study used data collected in 1965, 1969, 1974, 2000 and the most recent assessment in 2004-05. The number of participants varied at each assessment time, ranging from 10,979 to 15,051. Paternal involvement was principally assessed in 1969 when the children were about 11 years old. Mothers were asked about levels of fatherly involvement with possible responses of ‘inapplicable’, ‘leaves it to mother’, ‘significant but less than mother’, or ‘equal to mother’. When this data was cross-checked with other data from the cohort period, it was found that in 86% of cases the response ‘inapplicable’ referred to the father not living in the household with the child.

Socioeconomic status was assessed using a system of five occupational classes common in British National Statistics (I = professional through to V = unskilled). Social mobility was assessed by comparing the child’s social class in 2000 with that of the father in 1958. The IQ measure was a general ability (GA) score taken at age 11 (details of assessment not given in this report), which is said to have high validity with educational and occupational attainment. The researcher looked at relationships between GA score and paternal involvement, including other variables such as number of brothers and sisters.

What were the results of the study?

Level of paternal involvement varied by socioeconomic class, with 65% of class I fathers spending an ‘equal to mother’ amount of time with the child compared to 59% of class V fathers. Fathers who ‘left it to mother’ increased from 4% in class I to 14% in class V. If a child was a girl, they had significantly increased odds that their father would be in a category other than ‘equal to mother’. Odds also increased with each additional brother in the family, i.e. ‘greater numbers of siblings were associated with lower paternal involvement’. Overall, fathers invested more time with the child when they were of higher socioeconomic status, when the child was a boy, and when there were fewer children in the household.

As expected, IQ at 11 varied with child sex (girls scoring higher than boys), number of brothers and sisters (more siblings associated with lower score), and the father’s social class (higher class associated with higher IQ). The father’s role at age 11 also had an effect on IQ, with greater involvement associated with higher IQ. There was also an interaction between the father’s role and their social class, with greater paternal involvement having a larger effect on IQ when the father was of a higher social class.

There was also a significant effect of paternal involvement on their offspring’s social mobility (at age 42 years), with those who received more fatherly involvement more likely to increase social class (in addition to other expected patterns, e.g. males being more socially mobile than females, more siblings associated with less mobility). The author then goes on to discuss the psychology and social patterns that influence fatherly involvement.

What interpretations did the researchers draw from these results?

The author concludes that the study has demonstrated that increased paternal involvement positively influences the child’s IQ at age 11 and their level of social mobility at the age of 42. There was also an effect of socioeconomic status, with fathers of higher socioeconomic status spending more time with their children. It was also found that fathers of higher socioeconomic status who had more contact with their children had greater influence on the child’s IQ than fathers of lower socioeconomic status who spent equivalent amounts of time with their children. There were no differences seen between sons and daughters in terms of the effect that their father’s time had on them.

What does the NHS Knowledge Service make of this study?

This study has detected interesting patterns between fatherly involvement and child’s IQ. However the study has some important limitations:

• This study relied on the mothers’ perspectives of the fathers’ involvement and only measured this once in 1969. There are three problems: firstly, the mothers’ responses may have been inaccurate. Secondly, a single assessment made on one day is unlikely to be representative of the entire duration of the child’s upbringing. Thirdly, the results cannot be easily generalised to present day parenting. The level of contact and type of relationship that today’s children have with their fathers may be quite different from the norm in the 1950s and 60s. Forty to 50 years ago it was more common for a mother to stay at home with the children and for her to take a dominant role in bringing up children while the father went to work. Today, roles are more equal.
• Mother’s were only given a limited number of responses for the question on how involved the fathers were in their child’s upbringing. The responses will have been highly individual and will not mean the same thing from one family to the next. For example, ‘equal to mother’ could mean that the child was receiving high levels of attention from both of their parents. However, the same response could also be used if both parents were working full time and were both giving the child less attention.
• It cannot be assumed that it is only contact with the father that has an effect, or whether the same would be seen with any supportive male role model. It is also not possible to say whether it has to be a male at all, as the amount of time that the child spent with the mother or other adult females was not assessed. The questionnaire only compared the father’s involvement with that of the mother’s. If it had also directly measured the mother’s involvement then greater confidence could be had in this study.
• The effects of other factors such as the parents’ education, schooling, peer groups, disruptive life events or medical comorbidity and school absence were not investigated. The level of intelligence and professional career that a child develops depends on a wide range of factors, including genetics, education, peer group, and the home and external environment in which they grow up.