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Cradling is an interactive activity, involving a manual component that is very often an integral part of cradling. Cradling, while doing something else with the free hand, is referred to here as functional cradling. This study examined the relationship between a person's handedness and what arm he or she prefers to use when functionally cradling a baby doll that resembles a newborn infant. A total of 765 participants took part in the experiment, 403 women and 362 men, between the ages of 4 and 86 years. Left- and mixed-handers were actively recruited. The sample consisted of 64.3% right-handed, 24.7% mixed-handed, and 11.0% left-handed participants. The results showed a clear tendency for participants to cradle in their non-dominant arm (p < .001). Furthermore, this tendency increased with age and it was present in both sexes, although significantly stronger in women than in men. On the other hand, experience with young children through younger siblings and/or being a parent did not increase the likelihood to cradle in the non-dominant arm. It is concluded that humans have a clear functional cradling preference for the non-dominant arm because this enables the dominant arm to engage in other tasks. This might also explain why previous studies have reported a universal left cradling bias because a right-handed majority (intuitively) keeps the dominant hand free when cradling.

To write by hand, to type, or to draw – which of these strategies is the most efficient for optimal learning in the classroom? As digital devices are increasingly replacing traditional writing by hand, it is crucial to examine the long-term implications of this practice. High-density electroencephalogram (HD EEG) was used in 12 young adults and 12, 12-year-old children to study brain electrical activity as they were writing in cursive by hand, typewriting, or drawing visually presented words that were varying in difficulty. Analyses of temporal spectral evolution (TSE, i.e., time-dependent amplitude changes) were performed on EEG data recorded with a 256-channel sensor array. For young adults, we found that when writing by hand using a digital pen on a touchscreen, brain areas in the parietal and central regions showed event-related synchronized activity in the theta range. Existing literature suggests that such oscillatory neuronal activity in these particular brain areas is important for memory and for the encoding of new information and, therefore, provides the brain with optimal conditions for learning. When drawing, we found similar activation patterns in the parietal areas, in addition to event-related desynchronization in the alpha/beta range, suggesting both similarities but also slight differences in activation patterns when drawing and writing by hand. When typewriting on a keyboard, we found event-related desynchronized activity in the theta range and, to a lesser extent, in the alpha range in parietal and central brain regions. However, as this activity was desynchronized and differed from when writing by hand and drawing, its relation to learning remains unclear. For 12-year-old children, the same activation patterns were found, but to a lesser extent. We suggest that children, from an early age, must be exposed to handwriting and drawing activities in school to establish the neuronal oscillation patterns that are beneficial for learning. We conclude that because of the benefits of sensory-motor integration due to the larger involvement of the senses as well as fine and precisely controlled hand movements when writing by hand and when drawing, it is vital to maintain both activities in a learning environment to facilitate and optimize learning.

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Developmental psychology has a long history of linking motor development to enhancement in perceptual and cognitive abilities. Because of the haphazard appearance of the very first movements, the human infant is often thought to be born with an immature brain. However, behavioral and brain research shows that infants have advanced brains that are ready to learn even before birth. The infant brain doubles in both size and weight during the first year of life. During infancy, nerve cells increase dramatically in number, they become more specialized, and up to a thousand new connections per second are formed between them. The foundation for the brain’s infrastructure is formed during the first thousand days of life. Different neural networks are formed in response to the quantity and quality of experiences a child is exposed to. In addition, the growing brain is open and moldable, it can adapt to the changing conditions surrounding it, and the brains of infants and small children show the most plasticity. Developmental neuroscience research suggests that as soon as babies start crawling at around 9 months of age, they undergo remarkable development of prospective control and timing skills at both the brain and behavioral levels when dealing with visual motion. Only a few weeks after crawling onset, infants process visual motion faster and more efficiently, and they differentiate between motion speeds and directions. Stimulating the development of motor skills that allow babies to start exploring their surroundings by themselves earlier is therefore likely to facilitate brain development.