Only child

An only child is a person with no siblings. This status can occur through birth or through adoption. Throughout much of human history, only children were relatively uncommon. Most families tended to have multiple children. However, global trends shifted around the middle of the 20th century. Birth rates and average family sizes fell sharply during this period. This change happened for several reasons. People became concerned about human overpopulation. Additionally, more women entered the workforce. Many women also began having their first child later in life due to birth control.

Families may have an only child for many specific reasons. Some parents choose this based on personal preference or family planning. Financial constraints can also limit family size. Emotional or physical health issues might play a role. Some parents desire more time to travel or seek greater family stability. Other factors include time constraints, late marriage, or advanced age. In some cases, infertility or divorce leads to a single-child household. Historically, the premature death of a parent also contributed to smaller families. This was especially true before the mid-20th century when divorce was rare.

Different nations have experienced unique historical patterns regarding only children. In the United States, the proportion of only-child families increased during the Great Depression. This number fell later during the Post–World War II baby boom. After the Korean War ended in 1953, the South Korean government took a different approach. They suggested citizens have only one or two children to boost economic prosperity. This led to significantly reduced birth rates in South Korea. In the People's Republic of China, the government implemented the one-child policy from 1980 to 2015. This policy restricted most parents to one child, though some local relaxations existed. The policy ended in 2015, but it was linked to serious issues like gender imbalance.

Many social stereotypes exist regarding only children. In Western countries, people often label them as "spoiled brats." A commentator named G. Stanley Hall once called the situation a "disease in itself." In China, some referred to perceived behavioral problems as "Little Emperor Syndrome." Some people believe only children struggle with cooperation or social roles. They may also face extra pressure to be perfectionists. However, many scientists argue these views are myths. Social psychologist Susan Newman states that hundreds of studies show only children are no different from their peers. Most research does not support these negative views.

Psychologists use different models to study child development. The Resource Dilution Model suggests that parental resources are finite. This means children with many siblings might receive less time or attention. Conversely, the Confluence Model suggests that older siblings gain benefits by tutoring younger ones. Research by Toni Falbo and Denise Polit offers another perspective. They studied 115 different studies regarding personality and intelligence. They found that only children often surpassed others in many categories. One major finding was that the parent-child relationship is often stronger in only-child families. This strong bond can lead to positive developmental outcomes.

Scientific studies have examined specific personality traits in only children. A 1987 review of 141 studies looked at 16 different personality traits. It found no evidence that only children are more maladjusted due to pampering. The study did find one significant difference. Only children showed a higher achievement motivation. Researchers Denise Polit and Toni Falbo attributed this to greater parental resources and scrutiny. They also found that only children and first-borns often score higher on verbal ability tests. A large study of 8,689 people found no evidence that only children are more narcissistic. These findings suggest that birth order does not dictate personality as much as once thought.

Recent research has explored the long-term effects of being an only child. A 2011 study by Cameron et al. looked at children raised under China's one-child policy. These individuals were found to be less trusting and less likely to take risks. They also appeared less optimistic and more prone to neuroticism. The study suggested that interacting with cousins or childcare was not a substitute for having siblings. Another researcher, Frank Sulloway, suggested birth order influences the "Big Five" personality traits. He argued only children are more conscientious and socially dominant. However, other large studies have challenged these conclusions. They found no strong association between birth order and personality test scores.