I'm not sure that the idea of following a path of words that sound alike but mean something different would be the way to go with this one. When you talk about words in different languages, then you are going to end up with words that sound similar from time to time but have no similar meanings. Its simply a coincidence unless you are looking at words that have the same etymology - in which case their meanings are likely to be similar. I think you would be better off, if you want to go in a different direction, picking some aspect of language that is common among all cultures and looking at how it evolved. For example, the saying "good fences bring good neighbors" can be found in at least 10 different cultures, albeit states slightly differently, dating all the way back to ancient Rome. The fact that this concept is one that exists and has grown throughout so many diverse areas is something that might be interesting to look at. Also, you could consider looking at something such as the way in which we address one another as a show of respect. In French for instance, "vous" is used if to mean "you" if the speaker does not know  the person to whom he or she is speaking well, but "tu" is used when there is a greater degree of familiarity. The English language makes no such distinction. American English, in particular, is far less formal - indicating a slightly smaller divide between individuals and social classes, perhaps? This might be something to look at. You could take two cultures and parallel the formality of the society itself and the distinctions that exist within  it to the language that fosters or encourages those distinctions. These are just a few ideas that might help you get started.