According to a study out of Bangkok, one in every four Thai men have more than one what?

In Thailand, despite a legal ban on polygamy enacted in 1935, the practice of men having more than one wife continues informally. While the law mandates monogamy, many Thai men maintain relationships with secondary partners, often referred to as "mia noi" or "minor wives," who are not officially registered in a civil marriage. This enduring social phenomenon, even without legal recognition, explains why a study might report a significant number of Thai men with multiple wives.

Historically, polygyny was a widely accepted and legally recognized practice in Thailand, particularly among the nobility and royalty. Having multiple wives was often a symbol of a man's wealth, power, and social status, and it served practical purposes such as strengthening political alliances and ensuring lineage continuity. The shift to a monogamous legal system in the early 20th century was influenced by Western legal reforms, aiming to modernize family structures.

However, deeply rooted cultural traditions and societal norms have allowed de facto polygamy to persist. These informal unions, while lacking the legal protections and inheritance rights of a registered marriage, are often socially tolerated. Economic factors, such as a man's ability to financially support multiple households, can also contribute to the continuation of this practice, particularly among affluent individuals or in certain rural and Muslim-majority communities where religious customs may allow for it, albeit without full national civil enforcement.