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PubMed1983

Attitudes toward abortion and contraception among Nigerian secondary school girls.

A study of the attitudes of school girls in Benin City, Nigeria, toward abortion and contraception was carried out in three of the city's postprimary schools, using a uniform multiple-choice questionnaire. The findings show that although a significant proportion of the school girls had resorted to abortion to solve their problem of unwanted pregnancy, liberalized abortion law was only favored by a minority (approx. 30%). Also, although this indicated a high rate of sexual activity, their knowledge and practice of contraception and contraceptive methods is deficient and prejudiced. The latter findings may be responsible for the high rate of abortion among school girls in Nigeria.

Abortion, Induced↗
PubMed1989

Sexual behavior and contraceptive risk taking among sexually active adolescent females.

Drawing on DeLamater's conceptual model of premarital contraceptive activity, this study assessed the relationships between various social, developmental, and behavioral variables and contraceptive risk taking by sexually active adolescent females. The hypotheses were tested on a national random sample of unmarried sexually active adolescent females (n = 1512) ages 15-20 years from Cycle III of the National Survey of Family Growth. The number of years the subjects had been sexually active was the strongest predictor of their frequency of sexual intercourse, followed by their frequency of attendance at religious services. The inverse relationship between religious attendance and coital frequency was much stronger among whites than blacks. When the influence of these variables on contraceptive risk taking was assessed, coital frequency explained 7.2% of the variation in contraceptive risk taking, with the number of years the adolescent had been dating explaining a small amount of additional variation. Our data support not only the first stage of DeLamater's conceptual model of premarital contraceptive activity, but also aspects of Jessor's more general theory of adolescent risk taking and problem behavior.

Adolescent↗
PubMed2006

Maternal androgens in eggs of communally breeding guira cuckoos (Guira guira).

Variation of maternal androgens in avian eggs may be a mechanism of maternal influence on offspring development, growth, and/or behavior. We studied yolk androgen concentrations in eggs of guira cuckoos (Guira guira) to understand how females might enhance the success of offspring in a complex communal breeding system. We measured concentrations of androstenedione, 5alpha-dihydrotestosterone, and testosterone in yolks and identified eggs and clutches of individuals in joint nests by yolk protein electrophoresis. Androstenedione had the highest yolk concentration, at least 10 times higher than that of testosterone and 5alpha-dihydrotestosterone. The first eggs of individual females that laid two or three eggs in a joint nest had lower androstenedione concentrations than their second and third eggs, the latter having a lower probability of being ejected from the nest. This implies that guira cuckoo females may influence offspring survival and competitiveness in communal nests by means of differential allocation of androstenedione and laying tactics. There was significant variation in yolk androstenedione among females, but the order in which females entered laying in the communal clutch had no effect on the concentrations. Androstenedione yolk concentrations increased with communal clutch size, which may indicate that higher levels of competition in larger groups lead to higher yolk androgen concentrations. Finally, androstenedione concentrations were higher in clutches in the later wetter periods of the rainy season than during the earlier drier period. This may be explained by the high frequency of large clutches in the later periods, with more females contributing to a joint clutch.

Androgens↗
PubMed2003

Parasite manipulation of the proximate mechanisms that mediate social behavior in vertebrates.

Paul MacLean was instrumental in establishing the brain regions that mediate the expression of social behaviors in vertebrates. Pathogens can exploit these central mechanisms to alter host social behaviors, including aggressive, reproductive, and parental behaviors. Although some behavioral changes after infection are mediated by the host (e.g., sickness behaviors), other behavioral modifications are mediated by the pathogen to facilitate transmission. The goal of this review is to provide examples of parasite-mediated changes in social behavior and to illustrate that parasites affect host behavior by infecting neurons, causing central nervous system (CNS) inflammation, and altering neurotransmitter and hormonal communication. Secondarily, a comparative approach will be used to demonstrate that the effects of parasites on social behavior are retained across several classes of vertebrates possibly because parasites affect the phylogenetically primitive structures of the limbic system and related neurochemical systems.

Animals↗
PubMed1989

Age at first intercourse.

In 1984-85 a representative sample of 286 Danish women and 336 men aged 16-20 years were interviewed about their sexual debut. Seventy-four females (25.9%) and 101 males (30.1%) had not yet experienced sexual intercourse. A maximum likelihood estimation method was used to establish the age distribution at sexual debut. This takes into account knowledge of age at interview among the non-experienced respondents and of the few who did not report age at sexual debut. The median age at first sexual intercourse was close to 16.8 years for both females and males. This appeared to be a consequence of age at debut declining among women and remaining unchanged among males during the preceding 20 years.

Adolescent↗
PubMed1996

Contraceptive methods: do Hispanic adolescents and their family planning care providers think about contraceptive methods the same way?

This article describes how a family planning clinic-based program to prevent repeat pregnancy among Hispanic adolescents in Los Angeles used qualitative research to understand client contraceptive behavior. Background information on Hispanic adolescent reproductive patterns and an overview of paths to motherhood among teen clients are provided to contextualize the results. Participants sorted contraceptive methods on perceived similarities and ranked them on effectiveness, safety, and use-preference. Multidimensional scaling was used to identify and compare conceptual models. Both providers and teens grouped methods by effectiveness and mode of action, but acceptability and ease of method use were also important for teens. Providers found participation a worthwhile educational experience that facilitated self-reflection about their own biases and better understanding of their clients' needs. This method could be applied in many clinical settings where education and counseling are important in treatment and where patients and providers are likely to have different conceptual models regarding therapy.

Adolescent↗
PubMed1997

Pregnant and parenting adolescents and their younger sisters: the influence of relationship qualities for younger sister outcomes.

On the basis of social modeling theory and a sibling interaction hypothesis, it was hypothesized that specific relationship qualities between a pregnant or parenting teen and her younger sister would be associated with permissive younger sister outcomes, such as permissive childbearing attitudes and permissive sexual behavior. Results indicated that negative relationship qualities, such as rivalry, competition, and conflict, were more closely related to younger sisters engaging in problem delinquent-like behavior and sexual behavior than were positive relationship qualities, such as warmth and closeness. Additionally, a shared friendship network with the older sister was found to be associated with extensive younger sister problem behavior and sexual behavior. Three potential explanatory processes are discussed.

Adolescent↗
PubMedDate not supplied

Teenagers' perceptions of unplanned adolescent pregnancies and oral contraceptive use.

Adolescent women who are sexually active often do not use contraceptives consistently and correctly. Adolescents are sexually active for an average of 15 months before initiating regular contraceptive use and the majority of young women who initiate use discontinue within the first year after initiation. This study enrolled 50 young women who initiated oral contraceptive use and was designed to provide more understanding of their perceptions about the possibility of an unplanned pregnancy and about contraceptive use. They were again contacted 6 weeks after initiation of oral contraceptives to assess continuation. Findings revealed that 90% of the subjects were sexually active at the time of the first visit; the mean period of sexual activity was 15 months. Only 30% had used a nonprescription birth control method during this period. While perceiving themselves to be highly susceptible to pregnancy, many young women continue to have psychosocial barriers to contraceptive use. Follow-up contact revealed more than 10% of the subjects were not using oral contraceptives.

Adolescent↗
PubMed2005

Ecological change, group territoriality, and population dynamics in Serengeti lions.

Territorial behavior is expected to buffer populations against short-term environmental perturbations, but we have found that group living in African lions causes a complex response to long-term ecological change. Despite numerous gradual changes in prey availability and vegetative cover, regional populations of Serengeti lions remained stable for 10- to 20-year periods and only shifted to new equilibria in sudden leaps. Although gradually improving environmental conditions provided sufficient resources to permit the subdivision of preexisting territories, regional lion populations did not expand until short-term conditions supplied enough prey to generate large cohorts of surviving young. The results of a simulation model show that the observed pattern of "saltatory equilibria" results from the lions' grouping behavior.

Algorithms↗
PubMed1981

Teenage pregnancy in perspective.

In an effort to provide the clinician with suggestions for preventive and remedial approaches to adolescent pregnancy, the nature, medical, social, economic, and psychological aspects of the problem are reviewed and discussed. While the rate of adolescent pregnancy is declining, there are more than 560,000 deliveries to teenagers annually. Medical risks are significantly diminished by early and comprehensive prenatal care. The major complications continue to be social and economic. Lower I.Q.s in offspring of adolescent mothers have been reported. Failure to complete high school significantly increases the risk of unemployment, trapping the premature parent and her offspring in a web of poverty. A lack of a sense of future and viable alternatives may legitimize the option of motherhood in the minds of many adolescent girls. Furthermore, an ignorance and a denial of sexuality combined with the developmental imperatives of experimentation and rebellion place the adolescent at high risk for pregnancy.

Adolescent↗
PubMed1995

Ever-pregnant and never-pregnant teens in a temporary housing shelter.

Adolescent pregnancy and childbearing are of national concern; documented sequelae are numerous and varied. The primary purpose of this cross-sectional study is to describe the differences in selected demographic, sociocultural, physiological, psychological, and cognitive variables among 136 ever-pregnant and never-pregnant teens residing in a temporary housing shelter. Teens who experienced a pregnancy had significantly higher chronological age, gynecological age, and school grade level in addition to reporting significantly greater histories of both rape and voluntary sexual activity than did never-pregnant teens. This study indicates that teen pregnancy is a major problem among adolescents in temporary housing shelters. Our findings provide guidance for clinical interventions and further research with this at-risk population.

Adolescent↗
PubMed1988

Dimensions of personality organization as predictors of teenage pregnancy risk.

Personality development as measured by Loevinger's Washington University Sentence Completion Test, The Friedman Developmental Level Scoring System for the Rorschach, The Urist Mutuality of Autonomy Scale, The Thematic Apperception Test, and indexes from a structured interview were able to discriminate between teenagers at high- and low-risk for pregnancy. In addition, these measures correlated significantly with each other and enabled a description and comparison of the personality characteristics of adolescents who are at risk for pregnancy and those who are not.

Adolescent↗