“…Crowdedness ratio of the home (number of persons divided by number of rooms) provided another index of economic level, as used in studies of SES effects in the United States (Bloom, Whiteman, & Deutsch, 1965;Deutsch, 1967;Tulkin, 1968;Tulkin & Newbrough, 1968), in Canada (Marjoribanks, 1972a), in England (Swift, 1967), and in Israel (Handel, 1973c;Yaffe & Smilansky, 1958).…”