Dr. Cynthia Colen wasn’t satisfied with the studies of the merits of breastfeeding versus bottle feeding that she sees in her work as Assistant Professor of Sociology at the Ohio State University (OSU). Her concern is selection bias, a situation that occurs when socioeconomic factors aren’t taken into consideration.

Selection bias means the baby-feeding habits of affluent women were compared to women of lesser financial means. Women of many races and ethnicities were compared equally. That educated women were compared to less educated. The body of research on the subject clearly indicates that women with more resources and greater flexibility of schedule are more likely to breastfeed and to do so for longer periods of time than others.

Another of Colen’s concerns is the short duration of previous studies. The value of breastfeeding to the babies was followed only as long as the babies were infants and toddlers. Colen wanted to see longer-term results.

Colen took matters into her own hands and devised a study that compared the health outcomes of siblings when one child was breastfed and another got the bottle. By comparing kids within the same family, selection bias was eliminated. She tracked these siblings beyond early childhood, looking for health and well-being outcomes of the siblings when they were between 4 and 14 years of age.

Most feeding-method comparison studies focus on one or all of 11 different outcomes so Colen used them, too.

Physical and emotional:


  • Intelligence
  • Math ability
  • Reading recognition
  • Scholastic competence
  • Vocabulary

Colen’s analysis found the expected differences when one family unit was compared to all the others but the story was different when differently fed siblings were compared within just their own family unit alone. Within a single family unit, there was no significant difference between siblings fed differently as infants. The single exception was asthma.

The rate of asthma was higher in breastfed siblings but Colen says the incidence of asthma was often self-reported and not the result of the medical diagnosis.

There is a national drive to breastfeed every baby for six months or longer but it’s a mission impossible for many women. Colen says, “Rather than placing the blame at their feet, let’s be more realistic about what breastfeeding does and doesn’t do.”

Breastfeeding may make a short-term impact on a baby’s earliest moments but Colen feels lasting, long-term benefits would be more likely if the focus were on issues such as adequate housing, parental employment, and school quality.

Source: Caldwell, Emily. “Breast-feeding Benefits Appear to be Overstated, According to Study of Siblings.” The Ohio State University Research and Innovative Communications. The Ohio State University. Feb 25, 2014. Web. Mar 11, 2014.