I'm analyzing data in which I have a dependent variable with two possible outcomes (yes or no) and an independent variable with five emotion conditions, neutral, angry, sad, ashamed, and afraid. The 2x5 table is not statistically significant with a chi-square test, (probably) because the outcomes for some conditions are very close together (e.g., the distribution of yes/no is very similar for ashamed and afraid). However, a pairwise comparison between only certain conditions (e.g., comparing neutral to sadness) does give significant chi-square results.
Is it allowed to do pairwise comparisons with chi-square when overall the test is insignificant? And are post hoc corrections (e.g. Bonferroni) necessary in this case?