{'fraction_non_alphanumeric': 0.037598204264870934, 'fraction_numerical': 0.04040404040404041, 'mean_word_length': 5.04406779661017, '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}}
The increasing use of theory in social gerontology: 1990-2004.

OBJECTIVES
To determine how often theory is used in published research in social gerontology, compare theory use over a 10-year period (1990-1994 to 2000-2004), and identify the theories most frequently used in social gerontology research.


METHODS
Systematic review of articles published in eight leading journals from 2000 to 2004 (N = 1,046) and comparison with a review conducted 10 years earlier.


RESULTS
Theory was mentioned in 39% of articles published from 2000 to 2004, representing a 12% increase in the use of theory over 10 years. This increase was driven by theories outside the core sociology of aging theories identified by Bengtson, V. L., Burgess, E. O., and Parrott, T. M. (1997). Theory, explanation, and a third generation of theoretical development in social gerontology. Journal of Gerontology: Social Sciences, 52B, S72-S88. The five most frequently used theories included the life course perspective, life-span developmental theories, role theory, exchange theory, and person-environment theory/ecological theories of aging. Commonly used models included stress process/stress and coping models, successful aging models, the Andersen behavioral model of health services use, models of control/self-efficacy/mastery, and disablement process models.


DISCUSSION
Theory use in social gerontology increased between 1990 and 2004, with a shift toward theories that cross disciplines. However, the majority of research in social gerontology continues to be atheoretical. Models are widely used as a supplement to or substitute for theory. Many of these models are currently being debated and elaborated, and over time, they may emerge as important theoretical contributions to social gerontology.