Myrtle McGraw described locomotor development as proceeding in a fixed sequence of stages.
a) Briefly describe the developmental changes she catalogued and discuss her explanation for that.
b) Explain Esther Thelen & Linda Smith’s different explanation for locomotor development and give examples of the empirical evidence they gathered from their research that disavows McGraw’s interpretation
The correct answer and explanation is :
a) Myrtle McGraw’s Description of Locomotor Development:
Myrtle McGraw, a pioneering developmental psychologist, proposed that locomotor development follows a fixed and sequential series of stages. According to McGraw, the progression of motor skills in infants follows a specific, predictable path. She cataloged a sequence of stages in which children first gain control of gross motor skills, like lifting their head, rolling over, sitting, crawling, and finally walking.
McGraw’s explanation for this sequence was largely rooted in a maturational perspective. She argued that motor development was driven by biological maturation and that the timing of developmental milestones was largely determined by genetic factors. In this view, maturation was considered the main driver of locomotor development, with environmental influences having less of an impact on the rate at which children progressed through the stages. For example, she believed that motor milestones were reached at certain ages due to the gradual maturation of the nervous system, muscles, and joints, which allowed for the execution of increasingly complex motor behaviors.
b) Esther Thelen & Linda Smith’s Explanation of Locomotor Development:
Esther Thelen and Linda Smith presented a different explanation for locomotor development, challenging McGraw’s maturational theory. They proposed that motor development is not solely driven by maturation but by the interaction of biological, environmental, and experiential factors. According to Thelen and Smith, motor development is a dynamic process shaped by multiple factors, including sensory feedback, environmental opportunities, and the child’s active exploration of their surroundings.
One key argument they made is that motor skills develop through a process of self-organization, where babies explore and refine their movement patterns through trial and error, rather than simply following a fixed, pre-determined sequence. This means that environmental factors and opportunities for movement play a significant role in how and when babies achieve motor milestones.
Empirical evidence supporting Thelen and Smith’s perspective includes their research with infants in controlled environments. One example is the stepping reflex studies, where Thelen demonstrated that infants who were deprived of the opportunity to practice walking by being suspended in water, for example, could not produce stepping movements as expected. However, when infants were provided with the right sensory feedback and support, they could eventually execute stepping movements in a controlled environment. This suggested that motor development is not purely driven by an internal maturation timetable but is a result of complex interactions between the baby’s body, environment, and experiences.
Their work provided substantial empirical evidence that disavows McGraw’s interpretation by showing that locomotor development is not a fixed, predetermined sequence but is highly influenced by interaction with the environment and individual experiences.