Complex dynamics in intimate partner violence: a time series study of 16 women.

Objective: Three theories attempt to explain the dynamics of intimate partner violence, each representing a different dynamic pattern of violence: periodic, chaotic, and random. But few studies assess violence and its potential predictors in real time or permit assessment of the dynamics of violence. The purpose of this exploratory study was to estimate the degree of complexity in patterns of violence and identify predictors of violent events.

Method: This time series study was conducted between September 2006 and April 2007 among 16 adult women presenting to a university-affiliated family health center who had experienced violence within the past month. Women completed a daily telephone assessment of household environment and marital relationship for 2 months. To assess the degree of complexity, 3 different measures were used. Lyapunov exponents and saturation of correlation dimension were used to approximate dynamic patterns. Vector autoregression identified prior-week predictors of violence. Results were pooled across the 16 subjects who provided daily reports using meta-analytic techniques.

Results: Most relationships exhibited complex dynamics, with all 3 distinct dynamic patterns found. The longer the relationship had lasted, the more predictable and periodic were its dynamics. The more frequent the violence, the more complex and sensitive to change were its dynamics. Comparing dynamic patterns, 3 distinct combinations of significant prior-day and prior-week associations were found.

Conclusions: Although complex dynamics were unrelated to duration of violence, there was a dynamic tension between (1) the duration of the relationship and its periodic temporal patterns and (2) the frequency of violence and its complex dynamics. Identification of dynamic patterns may aid understanding of the phenomena of intimate partner violence and lead to novel targeted screening, monitoring, and intervention/treatment approaches.