Answer
This study contains flaws and can be challenged for several reasons:
1. There are many complicated factors which can cause violent and criminal behavior that lasts into adulthood, and male children born to women who smoke during pregnancy may only be one of the many factors.
2. The sample may be biased and not representative. Women of different race, age, diet, health, habits, income, education etc. should all be considered for the study.
3. This study is likely to be observational on very limited samples, while a well designed experiment would be preferred. However, considering the length (18 years or more) and the number of variables (many are confounding), it may not be practical to perform such an experiment.
Work Step by Step
See explanations above.