When two different cultures meet, both parts could experience a culture shock at first glance. The things that make us different always stand out more than the ones that makes us similar.
The positive effects of this happening could be various. It could help one of the culturea understand things better, and view them from a different perspective, thus learning new things and expanding their knowledge.
The negative effecs could come with certain rituals and habits that may come across as shocking or disgusting.