Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Site Tools

  • AAAS
  • Subscribe
  • Feedback

Site Search

Search Advanced

Science 22 June 2007:
Vol. 316. no. 5832, p. 1717
DOI: 10.1126/science.1141493
Prev | Table of Contents | Next

Brevia

Explaining the Relation Between Birth Order and Intelligence

Petter Kristensen1,2* and Tor Bjerkedal3

Negative associations between birth order and intelligence level have been found in numerous studies. The explanation for this relation is not clear, and several hypotheses have been suggested. One family of hypotheses suggests that the relation is due to more-favorable family interaction and stimulation of low-birth-order children, whereas others claim that the effect is caused by prenatal gestational factors. We show that intelligence quotient (IQ) score levels among nearly 250,000 military conscripts were dependent on social rank in the family and not on birth order as such, providing support for a family interaction explanation.

1 National Institute of Occupational Health, N-0033 Oslo, Norway.
2 Section for Preventive Medicine and Epidemiology, University of Oslo, N-0318 Oslo, Norway.
3 Institute of Epidemiology, Norwegian Armed Forces Medical Services, N-0015 Oslo, Norway.

* To whom correspondence should be addressed. E-mail: petter.kristensen{at}stami.no

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Birth Weight and Cognitive Ability in Childhood Among Siblings and Nonsiblings.
S. Yang, J. Lynch, E. S. Susser, and D. A. Lawlor (2008)
Pediatrics 122, e350-e358
   Abstract »    Full Text »    PDF »
Sibling configuration and childhood growth in contemporary British families.
D. W Lawson and R. Mace (2008)
Int. J. Epidemiol.
   Abstract »    Full Text »    PDF »
Reproducing in Cities.
R. Mace (2008)
Science 319, 764-766
   Abstract »    Full Text »    PDF »
Born to Be Smarter.
(2007)
Journal Watch Psychiatry 2007, 1
   Full Text »


ADVERTISEMENT
Click Me!

ADVERTISEMENT
Click Me!

To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)