{'fraction_non_alphanumeric': 0.030405405405405407, 'fraction_numerical': 0.041666666666666664, 'mean_word_length': 5.003378378378378, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Cross-national and longitudinal evidence for a rapid decline in life satisfaction in adolescence.

INTRODUCTION
While several studies have documented a declining-with-age trend in life satisfaction in adolescence, cross-national and nationally representative longitudinal evidence is needed to establish the normative trajectory of life satisfaction during this critical developmental period.


METHODS
The Health Behaviour in School-Aged Children (HBSC) study of 10-16-year-olds included the Cantril Ladder life satisfaction measure in surveys of 43 countries between 2001 and 2014 (N = 752,620, 51% females). The UK Household Longitudinal Study (UKHLS) was used to assess within-person changes in life satisfaction from age 10 to 15 years among young people sampled between 2009 and 2018 (N = 8952, Obs. = 30,278).


RESULTS
Life satisfaction decreased by 0.61 SDs on average from ages 10 to 16 in the HBSC sample. A statistically significant decreasing-with-age trend was observed in each of the 43 countries examined. Females experienced a more pronounced decline in life satisfaction than males (0.75 SD vs. 0.46) on average, and a significantly larger decrease in life satisfaction among females was identified in 38 of 43 countries examined. Longitudinal analysis of adolescents from the UKHLS sample replicated this pattern: life satisfaction declined significantly by 0.5 SD between the ages of 10 and 15 and this decline was found to be steeper for females (0.76 SD) than for males (0.23SD).


CONCLUSIONS
The study findings enhance our understanding of the lifespan dynamics of life satisfaction and point to a potential universal decline in life satisfaction in adolescence. Understanding the developmental processes underlying this phenomenon will now be crucial.