Based on the analyses to date, there are the following main differences between Humanities and Social Science:
1. Time period: Humanities are more focused on earlier / historical periods; Social Science is relatively more focused on current issues or modern period (say since around 1800).
2. Basis of evidence: Humanities are primarily based on textual analyses / philology; Social Science is based more on non-textual research tools
3. Language Requirement: Almost as a result of #2 above, Humanities have strong language requirement; Social Science in general does not.
Based on these 3 criteria, there is a question really as to why History is counted as Social Science rather than Humanities - part of it could be aesthetics vs. truth claim (but this is hard to explain why philosophy and linguistics are still part of Humanities); maybe more relevant is just Family Resemblance - e.g. Linguistics needs to be closed to where all Languages are taught, Philosophy and Religion probably should be in the same groupings, while Social Science all grew out of History (either as auxiliary subjects like Archaeology or subjects using history as evidence such as Sociology).