Yet, when evaluating this study it is clear to see that it would be a serious misjudgement to take the findings of it as completely reliable and trustworthy. As with many studies, those involved have displayed their findings so that the reader is lead to believe that one factor causes the other, in this case day care causing heightened behavioural problems in children. These results are correlational; as one goes up the other rises accordingly but this still does not mean that one causes the other. It is an assumption/educated guess that day care causes more behavioural problems and therefore means that the findings are not strongly reliable. Furthermore, the data obtained in the study has been documented in such a way that it exaggerates the effects of day care on aggression. Children who were not in full-time day care but definitely for a substantial time (between 10 and 30 hours), most of whom, did not show any signs of amplified levels of aggression.
On the other hand, there were many aspects of this study which enhanced its reliability such as the fact that the participants were selected from relatively diverse locations and from different family types. This will have made the findings more applicable to real life as they are not relative to one area or family type. Finally, the data gathered was not retrospective, meaning that the results used for their conclusion were gained first hand by those carrying out the study so there is no chance of exaggeration, mistake or lying unlike if the parent was asked about care arrangements years ago.
As I have explained, there are two sides to this argument, a study which claims that it has found evidence to support the belief that day care can be beneficial for children is that by Clarke-Stewart et al. By observing 150 children who were starting school for the first time, the team were able to differentiate between those who had previously attended day care and those who were primarily cared for at home, for most of the time by their primary caregiver. They were able to see this difference because those who had been in day care showed signs that they were more comfortable in social situations, had advanced negotiating skills and could get on well with other children more successfully than those who had not.
Possible explanations for these findings are that by spending time around other children of a similar age, before attending school, allows an infant to learn how to behave in social situations during their sensitive period. This would make them more comfortable in this type of situation. This would be in comparison to children who spend the years before going to school at home with their mother and little experience in how to cope around children of a similar age.
Nevertheless, flaws in this experiment and explanation have been pointed out, causing its reliability to be questioned. Similarly with the opposing study I have explained, the findings are correlational so the psychologists have explained the results in such a way that it is suggested that one factor caused another when there is no tangible evidence to support that. Secondly, it could be a possibility that unsociable children inherit that trait from their parents and who therefore, due to their unsociability, do not want to place their children in day care, themselves, to avoid contact with others. Consequently, only outgoing children attend day care. Furthermore, in the study itself it is unclear whether the children were observed in different locations and from diverse family types.
Yet, the experiment did observe a reasonably large group of children which would make the findings more reliable.
Due to the similar amount and strength of evidence on both sides of the argument it would be very difficult to take a side on the issue using the studies available. There are many factors which could lead you to believe that the studies are unreliable and irrelevant but it would be almost impossible to prove either way unequivocally.