Thursday, July 10, 2008

Confirmation Bias ... again

I didn't expect to see another example of confirmation bias so soon after my previous post, but here it is again. I will discuss the annotated parts in bold (emphasis mine).

More remarrying, but number of break-ups also rising
By Melissa Sim
Straits Times, 10 July 2008

More people here are saying "I do" more than once.

Of the nearly 24,000 people who walked down the aisle last year, 17.5 per cent of grooms were remarrying and 15.3 per cent of brides were tying the knot again.[1]

The figures have been rising for several years. A decade ago, only about one in 10 marriages involved a partner who was remarrying. [2] Associate Professor Paulin Straughan, a sociologist at the National University of Singapore, said this trend[3] is a good sign.

"Even though people have had an unpleasant experience, they don't give up on the institution of marriage and they try again," she said.[4]

The typical repeat groom was 41 years old and a remarrying bride was 35 on average last year; older than first-time newlyweds aged 30 and 27 respectively.

For Muslims, the remarriage figure was even higher.

Slightly over a quarter who took the plunge last year were not doing so for the first time, according to figures released by Singapore's Department of Statistics yesterday.

It found that divorces rose in tandem with marriages - which swelled to a five-year high of 23,967.

There were 7,226 divorces and annulments last year, up from 7,061 in 2006, a far cry from the 4,888 dissolutions a decade back.[5]

The reason for divorce among non-Muslims however, remained the same: living apart, unreasonable behaviour and adultery.

More people are also marrying outside their ethnic groups, according to the report.

Of those who tied the know last year, 3,940 or 16.4 per cent did so with someone of another race.

Ten years ago, there were just 2,290 inter-ethnic marriages, which made up just 8.9 per cent of the marriages that year.

Close to half of the inter-ethnic marriages last year were between Chinese men and foreign brides from countries such as Vietnam and the Philippines. [6]

Said Prof Straughan: "Inter-ethnic marriages will be much more common in a cosmopolitan society. It shows the high racial-tolerance level and open-mindedness of society." [7]

She added, however, that there were concerns in the case of foreign brides. "If there are language and cultural barriers, I worry that the marriage will not last and there will be no marital satisfaction." [8]


If the population of a country is growing, whether through organic growth or immigration, it is expected that the number of marriages will increase. When the number of marriages increases, it is expected that the number of divorces will increase. When the number of divorces increases, it is also perfectly reasonable to expect that the number of remarriages will increase.

What matters is the rate of increase. Is the increase in the number of remarriages significantly more than the increase in the number of divorces?

Let's look at the data. 

10 years ago, 10% of marriages involved a partner who was remarrying [2]. Today, we are told that approximately 16% of marriages are of this variety [1] (we cannot use a simple average of 17.5% and 15.3% as we should be using a weighted average instead, so 16% is an estimate).

Therefore, there has been a 60% increase in marriages in which at least one partner was remarrying.

In constrast, divorces and annulments have increased by 47.8% [5] over the last 10 years.

At first blush, it would indeed appear that remarriages have increased proportionately more than divorces. Ah, but there is a pickle. Every divorce results in two divorcees, and by the definition of remarriages here, a remarriage may involve a person who is marrying for the first time. Divorcees do not necessarily remarry other divorcees.

The statement that remarriages have increased proportionately more than divorces can only be supported IF (and this is a big if) we assume that the ratio of divorcee-divorcee remarriages to divorcee-first timer remarriages has remained constant over the last 10 years. If proportionately more divorcees get remarried to single people rather than divorcees, we should expect the number of remarriages to increase proportionately more than divorces.

Unless we have better quality data with higher resolution, we cannot tell if the increased number of remarriages is indicative of anything except a trend in increasing absolute numbers [3], but this is a given considering the higher population. We certainly have no basis of saying that more people have decided that they don't want to give up on the institution of marriage [4]. Indeed, people may not have given up on the institution of marriage at all in the first place. There is no reason to lament the crumbling institution of marriage, and then brighten up at the thought that remarriage statistics appear to have shown that that is not the case.

Assuming that she has not been quoted out of context, Paulin Straughan appears to be interpreting the data in a way that suits her views on marriage, i.e. confirmation bias. Her view appears to be that increasing numbers of divorcees are now taking a second look at remarriage where before they might not have.

Instead of interpreting the increase in remarriages the way she has, I venture an alternative hypothesis. There has been no change in the mindset of divorcees towards remarriage. Instead, there has been a lessening of the stigma associated with divorce (supported by the higher divorce rate), and single people are now more open to marrying a divorcee. This has skewed the ratio of divorcee-first timer remarriages to divorcee-divorcee remarriages in favor of the former, which has led to an increase of remarriages that is proportionately more than the increase in divorces.

My hypothesis is falsifiable, and may turn out to be wrong. But in the absence of contradicting data, it is as good a hypothesis as Straughan's.

I'm not quite sure of what to make of [7]. [7] as a statement taken on its own is actually reasonable. The question is, how relevant is it to Singapore's context? Is the increasing number of mail order brides really indicative of greater tolerance [6]? Are we really that cosmopolitan of a society? This could be confirmation bias at work again.

I have a problem with statement [8]. As a sociologist, I would think that Straughan would be more concerned with spousal abuse and exploitation than marriage durability.

The report on marriages and divorces can be found here.

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