Final answer:
Developmental psychologists should consider the principle of nature versus nurture when evaluating the effects of poor parenting on behavior problems in children.
Step-by-step explanation:
One important scientific thinking principle that developmental psychologists should keep in mind when evaluating different explanations for the effects of poor parenting on behavior problems in children is to consider the principle of nature versus nurture. This principle addresses the relative influence of genetics (nature) and the environment (nurture) on the development of behavior problems in children.
When a child is being examined for behavioural issues, an incorrect diagnosis could result in a treatment that could actually be detrimental to the child's mental development. In addition to this, the developmental psychologists should consider how genetic factors interact with parenting practices and other environmental factors in order to fully understand the causes of behavior problems in children.