“Feeling older, walking slower - but only if someone's watching. Subjective age is associated with walking speed in the laboratory, but not in real life”, European Journal of Ageing, December 2018, Volume 15, Issue 4, pp 425–433

Notthoff N, Drewelies J, Kazanecka P, Steinhagen-Thiessen E, Norman K, Düzel S, Daumer M, Lindenberger U, Demuth I

The huge inter-individual differences in how people age have prompted
researchers to examine whether people’s own perception of how old they
are—their subjective age—could be a better predictor of relevant
outcomes than their actual chronological age. Indeed, how old people
feel does predict mortality hazards, and health-related measures such as
walking speed may account for this association. In the present study,
we extended this line of work by investigating whether subjective age
also predicts walking speed and running speed in daily life or whether
the predictive effects of subjective age for behavior manifest only
within a controlled performance situation. We used data from 80 older
participants (age range 62–82 years; M = 69.50, SD = 4.47)
from the Berlin Aging Study II (BASE-II). Subjective age was assessed
by self-report. Walking speed in the laboratory was measured with the
Timed Up and Go test, and walking speed and running speed in real life
were measured with an accelerometer. Results showed that compared to
participants who felt older, those who felt younger than they actually
were indeed walked faster in the laboratory, but they did not walk or
run faster in real life. These patterns of results held when age,
gender, education, BMI, comorbidity, depression, physical activity, and
cognition were covaried. We discuss the role of stereotype threat in
accounting for these results.