Universal bursty behaviour in human violent conflicts - PubMed (original) (raw)

Universal bursty behaviour in human violent conflicts

S Picoli et al. Sci Rep. 2014.

Abstract

Understanding the mechanisms and processes underlying the dynamics of collective violence is of considerable current interest. Recent studies indicated the presence of robust patterns characterizing the size and timing of violent events in human conflicts. Since the size and timing of violent events arises as the result of a dynamical process, we explore the possibility of unifying these observations. By analyzing available catalogs on violent events in Iraq (2003-2005), Afghanistan (2008-2010) and Northern Ireland (1969-2001), we show that the inter-event time distributions (calculated for a range of minimum sizes) obeys approximately a simple scaling law which holds for more than three orders of magnitude. This robust pattern suggests a hierarchical organization in size and time providing a unified picture of the dynamics of violent conflicts.

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Figures

Figure 1

Figure 1. Event sizes and inter-event times.

The estimated number of deaths s (in logarithmic scale) in a given event occurred at time t (in days, counted from a given initial day) for conflicts occurred in (a) Iraq, with s ≥ 8 in the period 2003–2005; (b) Northern Ireland, s ≥ 4 (1969–2001); and (c) Afghanistan, s ≥ 1 (2008–2010). The growth curves represent the cumulative number of events, n(t). For comparison, 〈_r_〉 = 0.30 (Iraq); 〈_r_〉 = 0.01 (Northern Ireland); and 〈_r_〉 = 0.12 (Afghanistan), where 〈_r_〉 is the mean activity rate for the given values of minimum size. (d) Inter-event times τ obtained from the data shown in (a), (b) and (c) for the corresponding values of minimum size.

Figure 2

Figure 2. Inter-event time distributions with and without data rescaling.

(a) Inter-event time distribution, P(τ), calculated for the distinct conflicts (Iraq, N. Ireland and Afghanistan) and different minimum sizes. (b) The same data, but using the scaled variables 〈r_〉_τ and 〈r_〉−1_P(τ). The dashed lines are power-law decays–with exponent 0.75 for small times and with exponent 2.6 for large times.

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