The thinking skills of first-born children outdo those of their siblings because they are given more mental stimulation by their parents during their early years, a new study suggests. First-borns attained a higher score compared to their siblings upon taking IQ tests as early as age one.
In the study published in the Journal of Human Resources, first-born children were found to receive greater support when doing tasks that stimulated thinking skills, although the same levels of emotional support were given to all children. According to the researchers, such findings may contribute to explain the “birth order effect,” which highlights positive outcomes for first-born children later on in life, such as more education and higher incomes.
According to the research team from Edinburgh's Analysis Group as well as the University of Sydney, an increasing number of studies have continually found that birth order can impact one’s education and work-related opportunities. However, the underlying reason for such circumstances remains elusive. The University of Edinburgh's report noted that the family’s limited resources, including finances, may only favor the first-born children. Meanwhile, those who are born later may have to share such resources among each other.
Differences could be evident depending on the number of siblings and the size of the family. Moreover, children born later could still benefit if parents' income increases over the years, thereby favoring not only the first-born children but those born later on.
The study examined data on 4,850 children, who were observed prior to their birth until the age of 14. Majority of the sample were first-born children while only three percent were born last. Assessment on each child was carried out every two years. Multiple tests were conducted, including picture vocabulary evaluations, matching letters, and reading words aloud, to name a few. Information on family background, ethnicity and economic conditions were also considered.
Using statistical analysis and the Home Observation Measurement of the Environment as an assessment tool, the findings showed that first-born children enjoyed privileges early on in their life, starting after their birth up to age three. Slight differences were increasingly found with age, affecting test scores that assessed reading, verbal, comprehension and math abilities.
Another main point is the change of behavior among parents as the next children were born. They were found to offer less mental stimulation to the younger children and participated less in activities, such as reading one-on-one with the child or doing crafts, compared to a stronger involvement for their first-born children.
The mothers even took greater risks during their pregnancies for the subsequent children, including an increased occurrence of smoking. The study’s findings suggest that critical changes in parental behavior might provide an explanation for the evident birth order differences in outcomes relating to education and job opportunities, such as first-born children being found to enjoy more education and higher wages.
