In 1954, Notre Dame Professor, Rev John O'Brien, published a book called The Vanishing Irish, which purported to explain why Irish men were so reluctant to marry. Although he did not know it, O'Brien and his contributors were writing about a phenomenon that was about to disappear. Between 1963 and 1967, the number of marriages increased by 2 per cent annually; this trend accelerated in 1967, with the numbers marrying rising at an annual rate of 7.5 per cent. The peak in the marriage rate was in 1973 (birth numbers peaked in 1980). Between 1961 and 1971, the proportion of men aged twenty-five to thirty-four who were married increased from 42 to 58 per cent; the comparable figures for women were 63 and 74 per cent. Ireland belatedly experienced the post-war marriage boom, which was common throughout the Western world in the 1950s, but well past its peak by the early 1970s. Although sociologists continued to write about large numbers of permanently celibate Irishmen and women, these were an ageing cohort increasingly confined to small western farms; indeed, we might suggest that they were becoming more conspicuous because they no longer conformed to a norm. Greater prosperity, falling emigration and more jobs outside farming meant that couples could afford to marry and no longer had to wait until they could be sure of inheriting a farm. The fact that Ireland's belated marriage boom started in 1963, at the end of the First Programme for Economic Expansion, suggests that contrary to Rev O'Brien and his fellow contributors, Ireland's low marriage rate owed more to socio-economic circumstances than to psychology. Most brides now dressed in white, with bridesmaids in equally elaborate dresses – in marked contrast to the 1950s when many brides opted for a sensible suit or dress that could be worn on later occasions – further evidence of rising living standards, or simply greater optimism about the future.

The marriage boom was a major factor in Dublin's housing crisis. Stories of couples setting up home in caravans or in their parents’ home indicate a more optimistic, less cautious approach to embarking on married life than in the past, which may also reflect a psychological response to an improving economy, or the local impact of a growing youth culture and sexual revolution that is often seen as characteristic of the 1960s. Social lives of young people became less restrictive.