In some research on memory for words, the learner is exposed to stimuli to be remembered and later recalls those stimuli in the same order in which they initially appeared. This procedure is called serial learning. In general, when people must recall stimuli in a particular order, they remember less material than when allowed to engage in free recall, which imposes no constraints on the order or r…
When a person attempts to recall a set of stimuli that exceeds about seven items, there is a high likelihood that he or she will forget some of them. The generally accepted limit to memory for material that is not rehearsed is referred to as "the magic number seven" (plus or minus two items). Most studies in this area have employed lists of words or nonsense syllables, but the resear…
The most basic question of sex differences is whether the differences between the sexes are a result of our sex chromosomes, and genetic in nature, or did humans learn them from our social and cultural environments? This argument, usually referred to as the nature-nurture controversy, is one that is common in psychological work. Most psychologists attribute our differences to a combination of natu…
Men and women are different not only in anatomy, but also in terms of how they behave and in the interests they express. Certain behavioral differences are believed to be biologically determined. For example, the male sex hormone testosterone is believed to be the reason why males are considered more aggressive than females. However, many nonanatomical differences appear to be based on sex roles t…
Sex therapy, the treatment of sexual disorders, has evolved from early studies on sexual behavior made over 50 years ago. During these 50 years, the approach to sex therapy has changed immensely. When William Masters and Virginia Johnson published Human Sexual Inadequacy in 1970, the sexual revolution, born in the 1960s, was not yet in full force. Due in part to the development of the oral contrac…
Sexual abuse includes any sexual act or experience which is forced upon a person or which occurs as a result of coercion. In general, any sexual experience or exposure that occurs between a child and an older child, an adolescent, or an adult, for the gratification of the older individual, is considered to be sexual abuse. Sexual abuse includes rape, incest, inappropriate touching, exhibitionism, …
Sexual dysfunction involves both somatic and psychic phenomena which contribute to an overall inability or lack of interest in performing sexually. In males, the condition is most associated with erectile dysfunction (ED), formerly referred to as male "impotence." Studies estimate that 10-20 million American males have some degree of ED, which clinically presents as a persistent inab…
While sex is not necessary for an individual's survival, without it a species would cease to exist. The determinants of sexual motivation and behavior include an individual's physiology, learned behavior, the physical environment, and the social environment. A person's sex is determined at conception by whether one out of the 23 chromosomes in the father's sperm is eith…
In a career that spanned nearly 50 years, David Shakow conducted research that led to a vastly improved understanding of schizophrenia, one of the most complex mental disorders. Shakow's research covered all aspects of the disease, but in particular he focused on the mental deterioration that accompanied its progression. He was a strong advocate for patients of schizophrenia, which helped l…
Shaping, or behavior-shaping, is a variant of operant conditioning. Instead of waiting for a subject to exhibit a desired behavior, any behavior leading to the target behavior is rewarded. For example, B. F. Skinner (1904-1990) discovered that, in order to train a rat to push a lever, any movement in the direction of the lever had to be rewarded, until finally, the rat was trained to push a lever.…
William Herbert Sheldon developed "constitutional psychology," the study of the relationships between physical attributes and personality traits. To describe physical build, Sheldon studied thousands of photographs and developed a rating system for three major components or somatotypes—endomorphy, mesomorphy, and ectomorphy—and three secondary components. Likewise, he d…
As the first woman to earn a Ph.D. from the University of California, Milicent Shinn is credited today for her outstanding early American study, "Notes on the Development of a Child." First published in 1898 as a doctoral dissertation, this work is still hailed as a masterpiece and a classic in its field. A native Californian, Shinn was born in 1858 to parents who emigrated from the …
Most people, from social recluses to the rich and famous, probably have experienced feelings of shyness at various times in their lives. Physiological symptoms may include blushing, increased heart rate, sweating, and shaking. Just as these outward manifestations vary in type and intensity from person to person, so do the inner feelings. Anxious thoughts and worries, low self-esteem, self-criticis…
One of the early goals of psychologists was to measure the sensitivity of our sensory systems. This activity led to the development of the idea of a threshold, the least intense amount of stimulation needed for a person to be able to see, hear, feel, or detect the stimulus. Unfortunately, one of the problems with this concept was that even though the level of stimulation remained constant, people …
When researchers measure a behavior, they often compare groups to determine whether they differ on that behavior. The ultimate goal is to determine whether the difference would occur if the measurements were administered a second time, or whether the difference is accidental and not likely to recur. The degree of reliability relates to the concept of significance level. The significance level refe…
B. F. (Burrhus Frederic) Skinner was born in Susquehanna, Pennsylvania. As a youth, he showed talent for music and writing, as well as mechanical aptitude. He attended Hamilton College as an English major, with the goal of becoming a professional writer. After graduation, Skinner, discouraged over his literary prospects, became interested in behavioristic psychology after reading the works of John…
A healthy adult sleeps an average of 7.5 hours each night and most people (approximately 95 percent) sleep between 6.5 and 8.5 hours. Tracking brain waves with the aid of electroencephalographs (EEGs), researchers have identified six stages of sleep (including a pre-sleep stage), each characterized by distinctive brain-wave frequencies. Stage 0 is the prelude to sleep, which is characterized by lo…
An estimated 15 percent of Americans have chronic sleep problems, while about 10 percent have occasional trouble sleeping. Sleep disorders are listed among the clinical syndromes in Axis I of the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders. They may be either primary (unrelated to any other disorder, medical or psychological) or secondary (the re…
Olfaction is one of the two chemical senses: smell and taste. Both arise from interaction between chemical and receptor cells. In olfaction, the chemical is volatile, or airborne. Breathed in through the nostrils or taken in via the throat by chewing and swallowing, it passes through either the nose or an opening in the palate at the back of the mouth, and moves toward receptor cells located in th…
Social competence refers to the social, emotional, and cognitive skills and behaviors that children need for successful social adaptation. Despite this simple definition, social competence is an elusive concept, because the skills and behaviors required for healthy social development vary with the age of the child and with the demands of particular situations. A socially competent preschool child …
Human behavior is influenced by other people in countless ways and on a variety of levels. The mere presence of others—as co-actors or spectators—can stimulate or improve one's performance of a task, a process known as social facilitation (and also observed in non-human species). However, the increased level of arousal responsible for this phenomenon can backfire and create so…
Social learning theory has its roots in the behaviorist notion of human behavior as being determined by learning, particularly as shaped by reinforcement in the form of rewards or punishment. Early research in behaviorism conducted by Ivan Pavlov, John Watson, and B. F. Skinner used animals in a laboratory. Subsequently, researchers became dissatisfied with the capacity of their findings to fully …
Researchers have confirmed the conventional wisdom that first impressions are important. Studies show that first impressions are easily formed, difficult to change, and have a long-lasting influence. Rather than absorbing each piece of new information about an individual in a vacuum, it is common for people to invoke a preexisting prototype or schema based on some aspect of the person (for example…
Social psychology is the study of human interaction, including communication, cooperation, competition, leadership, and attitude development. Although the first textbooks on the subject of social psychology were published in the early 1900s, much of the foundation for social psychology studied in the 1990s is based on the work of the behavioral psychologists of the 1930s. Behavioral psychologists …
Socialization is a lifelong process that begins during infancy in the complex interaction between parent and child. As parents respond to a baby's physical requirements for food and shelter, they are also beginning to teach the baby what to expect from their environment and how to communicate their needs. The action-reaction cycle of smiling, cooing, and touching is a child's earlies…
In his 1975 work, Sociobiology: The New Synthesis, entomologist Edward O. Wilson first coined the term "sociobiology" to create a new field of study combining biology and social sciences, especially anthropology and sociology. Sociobiologists study the biological nature of human behavior and personality according to the tenet that all social behavior has a biological basis. The field…
Somnambulism, or sleepwalking, affects an estimated 15% of children in the early school years. It is similar to pavor nocturnus (night terrors) in that it occurs during the non-dreaming stage of sleep, usually within an hour or two of going to bed. The sleepwalking child feels an intense need to take action and may appear alert, purposeful, or anxious as he moves about. For many years, people beli…
Charles Edward Spearman was an influential psychologist who developed commonly used statistical measures and the statistical method known as factor analysis. His studies on the nature of human abilities led to his "two-factor" theory of intelligence. Whereas most psychologists believed that mental abilities were determined by various independent factors, Spearman concluded that gener…
Special education refers to a range of services, including social work services and rehabilitative counseling, provided to individuals with disabilities from ages 3-21 through the public school system, including instruction given in the classroom, at home, or in institutions. Special education classes are taught by teachers with professional certification. Some teachers specialize in working with …
Many different terms have been used to describe the disorder of childhood characterized by markedly delayed language development in the absence of any apparent handicapping conditions such as deafness, autism, or mental retardation. It is sometimes called childhood dysphasia, or developmental language disorder. Much research since the 1960s has attempted to identify clinical subtypes of the disord…