It turns out that time doesn't actually heal all wounds - at least when it comes to marital age gaps.

Good news if you're the younger half... New research, based on 13 years worth of data from thousands of Australian households, has revealed that both men and women both report being happier in their marriage with younger spouses. However, that satisfaction fades over time in marriages with a significant age gap between the partners, a team from the University of Colorado Boulder has found.   The findings also suggest that marriages with large age gaps are less resilient in the face of economic hardship when compared to spouses who are similarly-aged. Rather unsurprisingly, the findings show that men reported greater marital satisfaction when paired with a younger spouse, especially in the early years of marriage. But the reverse appears to be true as well, according to Professor Terra McKinnish:

"We find that men who are married to younger wives are the most satisfied, and men who are married to older wives are the least satisfied. Women are also particularly dissatisfied when they're married to older husbands and particularly satisfied if they're married to younger husbands."

McKinnish, a professor of economics at CU Boulder, says that initial satisfaction fades quickly, however, after six to ten years of marriage for couples with a big age gap between the partners:

"Over time, people who are married to a much older or younger spouse tend to have larger declines in marital satisfaction over time compared to those who are married to spouses who are similar in age."

One potential reason for this decline could be how the age difference between spouses affects a couple's ability to respond to economic shocks, such as a job loss, Professor McKinnish says:

"We looked at how couples respond to negative shocks and in particular, if they have a bad economic shock or worsening of their household finances. We found that when couples have a large age difference, they tend to have a much larger decline in marital satisfaction when faced with an economic shock than couples that have a very small age difference."

A possible explanation for this, McKinnish says, is that similarly-aged couples are more in sync on life decisions that affect both partners (for example having children and general spending habits) and thus may be better equipped to adjust to a negative financial shock. By contrast, an unexpected financial shakeup could expose underlying tensions and mismatches in couples with a larger age gap.