I'd agree with you, but. In 1950 the average family was very likely to live on a single income, the husband would be the earner and the wife a housewife.

I'd be curious to see the numbers for my assumption, though.

Yeah, from what I understand, inflation-adjusted family income has remained largely stable for the lower 80% despite significantly more families having more than one income, which sounds plausible, given that more supply should decrease the price of labor.