Impaired motor ability persists (and possibly worsens) as children with WS reach adolescence.Adults and adolescents with Williams syndrome typically achieve a below-average height and weight, compared with unaffected populations. As people with WS age, they frequently develop joint limitations and hypertonia, or abnormally increased muscle tone. Hypertension, gastrointestinal problems, and genitourinary symptoms often persist into adulthood, as well as cardiovascular problems. Adults  are typically limited in their ability to live independently or work in competitive employment settings, but this developmental impairment is attributed more to psychological symptoms than physiological problems. Social and psychological
People with Williams syndrome report higher anxiety levels as well as phobia development, which may be associated with hyperacusis (high sensitivity to certain frequencies of sound). Compared with other children with delays, those with Williams syndrome display a significantly greater number of fears. 35% of these children met the DSM definition of having a phobia as compared with 1–4.3% for those with other types of developmental delays. Williams syndrome is also strongly associated with attention deficit hyperactivity disorder and related psychological symptoms such as poor concentration, hyperactivity, and social disinhibition.Furthermore, cognitive abilities (IQs) of people with WMS typically range from mild to moderate levels of intellectual disability. One study of 306 children with Williams syndrome found IQ scores ranging from 40 to 112 with a mean of 69.32 (the mean IQ score of the general population is 100). IQ scores above this range have been reported in people with smaller genetic deletions.
Life expectancy is less than that of the general population, mostly due to the increased rates of heart disease. Signs and symptoms
The most common symptoms of Williams syndrome are heart defects and unusual facial features. Other symptoms include failure to gain weight appropriately in infancy (failure to thrive) and low muscle tone. People with WS tend to have widely spaced teeth, a long philtrum, and a flattened nasal bridge.Most people with WS are highly verbal relative to their intelligence, and are often very sociable, having what has been described as a "cocktail party"-type personality. People with Williams syndrome hyperfocus on the eyes of others in social engagements. Physical
People with WS experience many cardiac problems, commonly heart murmurs and the narrowing of major blood vessels, as well as supravalvular aortic stenosis. Other symptoms may include gastrointestinal problems, such as severe or prolonged colic, abdominal pain and diverticulitis, nocturnal enuresis (bed wetting) and urinary difficulties, dental irregularities and defective tooth enamel, and hormone problems, the most common being hypercalcemia. Hypothyroidism has been reported to occur in children, although no proof has been found of it occurring in adults; adults with WS have a higher risk of developing type-2 diabetes, with some cases apparent as young as 21 years old.People with WS often have hyperacusia and phonophobia, which resembles noise-induced hearing loss, but this may be due to a malfunctioning auditory nerve. People with WS can also tend to demonstrate a love of music, and they appear significantly more likely to possess absolute pitch.