For many years the notion that brain damage causes less impairment in
children than in adults (sometimes known as the 'Kennard Principle') h
as enjoyed widespread support among scientists and clinicians. More re
cently neuroscientists have questioned the Principle, most now taking
an opposing view that damage to the rapidly developing brain can be mo
re harmful than equivalent damage in adulthood. Many clinicians, howev
er, appear reluctant to reject the Kennard Principle. This study inves
tigates the extent to which the Kennard Principle still guides the jud
gement of different groups of health-care professionals (neurosurgeons
, neurologists, neuropsychologists, general practitioners, nurses, phy
siotherapists, occupational therapists, and speech therapists). Subjec
ts were asked to estimate the extent of recovery in clinically based b
ut fictitious case studies which differed only in the reported age of
the patient. The professions differed in their levels of optimism rega
rding the extent of recovery to be expected, but all predicted better
recovery in younger patients (under 10) than in adults with otherwise
similar brain injuries. The results are discussed in terms of their im
plications for the treatment of brain injuries in the young.