Chocolate and happy babies A University of Helsinki (Finland) study wanted to determine if chocolate consumption during pregnancy had an effect on infant temperament at age of 6 months. Researchers began by asking $305$ healthy pregnant women to report their chocolate consumption. Six months after birth, the researchers asked mothers to rate their infants’ temperament, including smiling, laughter, and fear. The babies born to women who had been eating chocolate daily during pregnancy were found to be more active and “positively reactive”—a measure that the investigators said encompasses traits like smiling and laughter.

(a) Was this an observational study or an experiment? Justify your answer.

(b) What are the explanatory and response variables?

(c) Does this study show that eating chocolate regularly during pregnancy helps produce infants with a good temperament? Explain.

Number of healthy pregnant women, $n=305$

The study found that babies born to mothers who ate chocolate every day during pregnancy were more active and positive in their reactions.

Observational research looks at people and assesses factors of interest without trying to affect their responses.

Because an observatory analysis retrieves information on the possible impact of individuals on a technique, this was an observational study. When the investigator has no influence over whether subjects are assigned to a treatment group or a control group. The researchers also questioned their chocolate consumption and attitudes toward newborns.

Because chocolate consumption by the mother helps to clarify the baby's disposition. The intake of mother chocolate and the nature of the infant are the explanation and response.

No. Because this is an observational study, it is impossible to conclude that chocolate consumption during pregnancy consistently results in children with healthy temperaments. The temperament difference could be influenced by a hidden factor.