Lack of Attachment to Mom May Cause Early Puberty in Girls

If you're still on the fence about how you feel about attachment parenting, new research findings about early puberty in girls may send you over the edge.

In a study published this week in Psychological Science, researchers suggest that babies who do not form a secure attachment to their mothers will be more likely to enter puberty early.

These findings are notable in light of growing evidence that girls in the United States are starting to mature at earlier ages than ever before -- even as young as 7 -- and both early puberty and poor infant attachment raise concerns, according to the Los Angeles Times.

Girls who enter puberty earlier are at higher risk for certain cancers, including breast cancer, and are likely to engage in sexual activity earlier, which increases the risk of sexually transmitted disease and early pregnancy. Poor attachment in infants has been linked to a higher risk of anxiety, depression and other psychological problems later in life.

Previous research has implicated other factors -- such as nutrition and obesity -- in the early onset of puberty in girls, but the researchers suggest infant bonding should be added to the list, according to the newspaper.

The study, based on data collected on 373 white female participants in the comprehensive National Institute of Child Health and Human Development (NICHD) Study of Early Child Care, was conducted by psychologist Jay Belsky of Birbeck University London and an international team of researchers.

To gauge whether babies were "securely attached" -- or emotionally distant -- from their mothers, researchers separated the babies from their mothers, and then reunited them and observed their reactions.

"A securely attached baby typically greeted her mother's return by smiling, vocalizing and reaching toward her parent; babies who looked away, fail to acknowledge or both advanced to and retreated from their mother upon her return were rated 'insecurely attached'," according to the Times.

Researchers found that the more "insecurely attached" to her mother a baby girl was at 15 months, the earlier she would enter puberty and mature sexually. These results were consistent regardless of when their mothers entered puberty -- a strong hereditary determinant in a girl's sexual maturation, according to the study.

Notably, baby girls who were not determined to be securely attached to their moms were nearly two-and-a-half times more likely to begin pubertal changes by the age of 10 1/2, and to have pubic hair, breast development and get their periods by 13 1/2, according to the Times.

The researchers theorize that the process of evolution may explain their findings. They suggest that insecure and unsupportive family relationships accelerate puberty, so that females can mate and reproduce earlier, which would give them an advantage in environments where survival -- and, therefore, reproduction -- may be comprised.

In secure and supportive family relationships, females would mature later, so mating and reproduction would occur later, giving them an advantage in environments where survival is less difficult, according to the study.

The Times reports that Belsky has spurred controversy with studies suggesting that long hours of child care for infants and young children outside the home may weaken a child's attachment to their primary caregiver -- usually Mom -- and negatively affect the child's later behavior at school.

"The importance of an infant's attachment to Mom is not widely debated. But debates have long raged over what factors -- a child's temperament, the mother's employment outside the home, a depressed parent -- may contribute to the security of that bond," the researchers say.

Related: More Girls Entering Puberty Early, Study Finds