Apart from collective nouns like police and cattle that always take a plural verb, there are different approaches taken in different countries where English is spoken. In American English, the general tendency is to use the singular. Indeed, some American speakers regard the plural as incorrect. In British English, the plural is much more widespread, though when the collective noun is seen as a single thing and not a collection of individuals, then the singular is preferred, so British speakers might say that a company is being sold, but may use the plural when thinking about the company's operations. The BBC states its policy is to use the plural when talking about a team, etc. In Australian English, the singular is becoming common than the plural, but both are used.
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As a language (such as English) becomes more complex at least in its vocabulary part of its grammar goes direction simplification. Although I personally use and prefer British English I must admit that the American way of seeing such nouns as singular is gaining more currency maybe partly because of American dominance. I do think making a distinction between a family as a unit (singular) or seen as group of individuals (plural) is either no more relevant or will not be relevant or needed anymore. Languages satisfy needs.