Ainsworth is known for taking a cross-cultural approach to studying child psychology. She implemented the same procedure of experiments in different cultures and then drew comparisons between the different places.
There is an issue with nature-nurture when it comes to drawing conclusions from these studies because if the same results are found then it suggest that they are due to nature (biological factors and universal laws) whereas if the results are different it suggests they are due to nature (culture) but this might not always be the case.
There is also reliability within the studies because the same procedures are used in the different cultures and culture is the only thing that changes. This means that they can be repeated to test for reliability in different countries.
The way that a procedure is understood is part of the findings, and this might differ between cultures. If the understanding of what’s required causes differences in findings then the findings are due to the study itself and not nature or nurture – this means that the validity needs to be questioned.
Standardised procedures which are set up to compare the behaviour are not likely to be valid because the behaviour is not typical of real life. Also, there may be differences in how the research is carried out because of different interpretations of researchers.