In a symbol-manipulating and culture-producing species, homosexuals fulfill the function of outliers not bound by responsibilities of family and to a certain degree free from regular societal norms and expectations. As such they are in a position to dedicate themselves to niche endeavors which may have no immediate useful function for society, but contribute to the experimentation and innovation which keep human culture evolving and adapting. They are often able to take bigger risks and pursue less profitable career-paths compared to heterosexual people with a family. Having children/spouses be dependent on your income makes you more conservative in taking risks and experimenting with your perceived role in society. Thus you can find many homosexuals in fields which demand extreme immersion and individuality of thinking in order to produce results: art and science.