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Topic Name: Researcher Says Family conditions may affect when girls experience puberty

Category: Biomedical

Research persons: Bruce J. Ellis, Ph.D.

Location: Division of Family Studies and Human Development, University of Arizona, United States

Details

Early puberty in girls has been found to negatively affect these teenagers’ health in areas such as mood disorders, substance abuse, adolescent pregnancy, and cancers of the reproductive system. Given these findings, it is critical to understand why certain adolescents are at increased risk for early puberty in order to develop effective early intervention and prevention strategies for high-risk youths.

New research shows that greater support from mothers and fathers, as well as less marital conflict and depression (as reported by fathers), can lead to later onset of puberty. The findings, from researchers at the University of Arizona and the University of Wisconsin–Madison, are published in the November/December 2007 issue of the journal Child Development.

The researchers sought to test and extend a 1991 model (developed by researcher Jay Belsky and colleagues) of the role of family ecology in speeding up or slowing down puberty in girls. According to Belsky’s theory, children’s early experiences affect how they mature, with certain stressors in and around the family creating conditions that speed puberty as well as sexual activity. These stressors include marital conflict, negativity and coercion in parent-child relationships, and lack of support between parents and children. According to the theory, children adaptively adjust their sexual development in response to the conditions in which they live.

To test this theory, the researchers investigated the effects of stressors on the timing of children’s development by examining families of 227 preschool children over a period of time. Specifically, they looked at the families’ socioeconomic conditions, marital conflict, parental depression, and supportive versus coercive parenting, through interviews with both mothers and fathers. The study followed the children through middle school, testing the first hormonal changes of puberty–the awakening of the adrenal glands–in 120 of the children (73 or whom were girls) when they were in first grade, and the development of secondary sexual characteristics–such as breast budding and the growth of body hair–in 180 girls when they were in fifth grade.

Children living in families with greater parental supportiveness (from both mothers and fathers) and less marital conflict and depression (but only when reported by fathers) experienced the first hormonal changes of puberty later than other children, the researchers found. In addition, children whose mothers had started puberty later (a genetic factor), whose families were better off when the children were in preschool, whose moms gave them more support when they were in preschool, and who had lower Body Mass Index (BMI) when they were in third grade developed secondary sexual characteristics later than their peers.

“Consistent with the theory, quality of parental investment emerged as a central feature of the proximal family environment in relation to the timing of puberty,” according to Bruce J. Ellis, associate professor of family studies and human development at the University of Arizona and the lead author of the study. “These results replicate and extend previous longitudinal research indicating that higher levels of positive investment and support in family relationships in preschool predict lower levels of pubertal maturation in daughters in the seventh grade.”

The study was funded, in part, by the National Institute of Mental Health.

Note for Puberty

Puberty refers to the process of physical changes by which a child's body becomes an adult body capable of reproduction. Puberty is initiated by hormone signals from the brain to the gonads (the ovaries and testes). In response, the gonads produce a variety of hormones that stimulate the growth, function, or transformation of brain, bones, muscle, skin, breasts, and reproductive organs. Growth accelerates in the first half of puberty and reaches completion by the end. Before puberty, body differences between boys and girls are almost entirely restricted to the genitalia. During puberty, major differences of size, shape, composition, and function develop in many body structures and systems. The most obvious of these are referred to as secondary sex characteristics.
In a strict sense, the term puberty (and this article) refers to the bodily changes of sexual maturation rather than the psychosocial and cultural aspects of adolescent development. Adolescence is the period of psychological and social transition between childhood and adulthood. Adolescence largely overlaps the period of puberty but its boundaries are less precisely defined and it refers as much to the psychosocial and cultural characteristics of development during the teen years as to the physical changes of puberty.

Note for mood disorder

A mood disorder is a condition whereby the prevailing emotional mood is distorted or inappropriate to the circumstances.
The two major types of mood disorders are depression (or unipolar depression) and bipolar disorder.
Depression (or unipolar depression), including subtypes: 
Major Depression 
Major Depression (Recurrent) 
Major Depression with psychotic symptoms (psychotic depression) 
Dysthymia 
Postpartum depression 
Bipolar disorder, a mood disorder formerly known as "manic depression" and described by alternating periods of mania and depression (and in some cases rapid cycling, mixed states, and psychotic symptoms). Subtypes include: 
Bipolar I 
Bipolar II 
Cyclothymia

Note for Substance abuse

Substance abuse refers to the use of any legal or illegal substance when that use is causing damage to the user's physical and/or mental health and causes the person legal, social, financial or other problems including endangering their lives or the lives of others. The phrase "problematic substance use" is a newer term for "substance abuse" that is gaining acceptance.

When science began to study addictive behavior in the 1930s, substance abusers were thought to be morally flawed and lacking in willpower.

About National Institute of Mental Health

The National Institute of Mental Health (NIMH) is part of the federal government of the United States and the largest research organization in the world specializing in mental illness. It is one of the 27 component organizations of the National Institutes of Health (NIH), which is in turn part of the U.S. Department of Health and Human Services. It was formally established in 1949 and research is conducted at a central campus in Bethesda, Maryland, as well as being funded throughout the United States. The stated mission of NIMH is to reduce the burden of mental illness and behavioral disorders through ('biomedical') research on mind, brain and behavior. NIMH is particularly known for studies of genetics, neuroscience and clinical trials of psychiatric medication.

About Researcher

Bruce J. Ellis, Ph.D. 
Associate Professor 
Division of Family Studies and Human Development 
Phone: (520) 626-5703 
Fax: (520) 621-3401 
Email: bjellis@email.arizona.edu

CAMPUS ADDRESS
Family and Consumer Sciences Bldg. 
1110 East South Campus Drive 
Tucson, AZ 85721 0033

Scholarly Interests and Activities 
Perhaps the most enduring mystery surrounding human sexual development and behavior is its variation. Some individuals complete pubertal development by the 5th grade while others are still relatively undeveloped when they graduate from high school; some begin sexual activity and reproduction as teenagers while others delay having children until decades later; some pursue short-term relationships with multiple partners while others commit to a single partner for life. 
My research seeks to understand the developmental causes and function of this variation. Using evolutionary theory as a framework for studying gene-environment interactions during development.