How many letters does the top answer for “relating to human society and its members” have?

The most common answer is social (6 letters).

Crossword clue: relating to human society and its members

2 answers found in Letterora's clue database (Wikidata facts, Open Trivia DB, WordNet and Webster definitions — all licensed sources).

social 6 letters wn-def

relating to human society and its members

societal 8 letters wn-def

relating to human society and its members

relating to a member. 50% similar → membral