First-born children are more intelligent than their siblings because they receive more mental stimulation in their early years, new research has shown. University of Edinburgh economists found that first-born children achieved higher IQ test scores.
The researchers examined data from 5,000 children. Every child was assessed every two years. The tests included reading recognition, such as matching letters and reading single words aloud. First-born children tended to score higher on verbal, reading, math and comprehension skills.
All children were found to receive the same level of emotional support, but parents appeared to spend less time on brain-stimulating activities with their younger children, took part in fewer activities with them such as reading, crafts and music.
Researchers said the findings could help to explain a phenomenon called the birth order effect which means children born earlier in a family have better wages and higher levels of education later in life.
Source article: http://iservice.ltn.com.tw/Service/english/english.php?engno=1077980&day=2017-02-14