Undoubtedly, some suicide terrorists are unstable, depressed individuals who want to die under the cover of martyrdom – not heroes who seek to sacrifice for others. Lankford's argument, however, is that all suicide terrorists are suicidal, and that we must therefore understand their individual life histories and psychological dispositions in order to better predict when and where future attacks are likely to occur (Lankford Reference Lankford2013c). Both halves of this argument are problematic, the first because support for his contention that suicide terrorists have a death wish is weak, and the second because understanding the organizational contexts in which most suicide terrorism occurs is likely to be more useful than psychological profiling for predicting future attacks.

As Lankford points out, mental health professionals have difficulty identifying potential suicides under the best of circumstances, and suicide terrorist recruits and their organizations rarely describe their actions in anything other than heroic terms. It is therefore unsurprising that researchers tend to report few clear instances of depression, instability, or other potential markers of suicidal tendencies among suicide terrorists (e.g., Atran Reference Atran2003; Pape Reference Pape2005). To make his case, then, Lankford is often reduced to suggesting that suicide terrorists must be suicidal simply because they are willing to die. For example, he argues that Merari's (Reference Merari2010) research team members ignored “the most obvious indicator that their subjects were suicidal: the fact that they had planned to blow themselves up” (Lankford Reference Lankford2013c, p. 50). In addition, he categorizes terrorists without apparent suicidal motivations as “indirectly” suicidal – that is, unconsciously seeking to die – apparently because a “hardwired survival instinct” should prevent stable individuals from engaging in high-risk behaviors (unless they are ignorant of the dangers). But non-suicidal individuals often engage in high-risk behaviors, and biases in information processing and decision making are aspects of normal psychology that can lead to under-assessments of health and mortality risks (e.g., Andersson & Lundborg Reference Andersson and Lundborg2007; more generally: Ditto Reference Ditto, Bayne and Fernandez2009; von Hippel & Trivers Reference von Hippel and Trivers2011). Further, an overarching survival instinct is unlikely to exist, as it is reproduction, and not survival for its own sake, that matters in terms of natural selection, and instincts appear to relate more to specific dangers associated with our evolutionary history than to death in general (Buss Reference Buss1997; Navarrete & Fessler Reference Navarrete and Fessler2005).

In fact, there are several models of altruism through which inclinations to sacrifice can be understood as part of normal human evolved psychology. One is kin selection theory, which explains how genes associated with behaviors that reduce individual fitness can nevertheless spread if the behaviors result in fitness benefits for genetic relatives (Hamilton Reference Hamilton1964; Park Reference Park2007). Hence, although associated mechanisms of kin dispersal and recognition will vary, dispositions to sacrifice for (some) others are likely normal in many species (Emlen Reference Emlen1995; Reference Emlen, Krebs and Davies1997), including humans (e.g., Madsen et al. Reference Madsen, Tunney, Fieldman, Plotkin, Dunbar, Richardson and McFarland2007). A related model, induced altruism through kinship deceit, describes how such dispositions can also lead to sacrifice for the benefit of non-relatives through the manipulation of kin-recognition cues (Trivers Reference Trivers1985). This model, too, may apply to humans if fictive kinship is reinforced through the manipulation of human kin-cues such as association, phenotypic similarity, and kin terms (e.g., Johnson Reference Johnson1986; Reference Johnson1989).

Thus, under certain circumstances, psychologically healthy individuals may be disposed to sacrifice their lives to benefit kin or non-kin with whom fictive kinship bonds are shared. In suicide terror contexts, altruistic dispositions are often reinforced through organizational structures and practices. Although leery of contextual explanations for suicide terrorism, Lankford does discuss the typical role of sponsoring organizations in facilitating suicide terrorist logistics (bombs and targets) and generating social approval for suicide terror as a strategy. He also notes instances of organizational coercion of suicide recruits. However, he overlooks the fact that organizations often rely on specific practices to reinforce commitment to the costly sacrifices they demand. Given the obvious difficulties associated with uncovering the psychological states and motivations of individuals, it makes more sense to focus on the structure and dynamics of the organizations of which these individuals are members to better identify potential suicide terror threats. For example, Atran has investigated the degree to which terrorist activity takes place in “networks of family and friends who die not just for a cause, but for each other” (Atran Reference Atran2013, online publication), and thus in the context of both real and “imagined” kinship. And as I have attempted to show, where relationships among suicide terrorists and their organizations and communities are less personal, even otherwise dissimilar organizations appear to share similar practices plausibly associated with the manipulation of human kinship recognition mechanisms to attempt to reinforce fictive kinship bonds among members (Qirko Reference Qirko2009; Reference Qirko2013). Terrorist organizations also often make use of other commitment-reinforcing practices, including offering material and status rewards to human bombers' relatives, appealing to afterlife rewards, and requiring recruits to execute public oaths and wills that make backing out difficult (Merari Reference Merari, Yufit and Lester2005).

In short, we can argue about the degree to which suicide bombers are healthy or suicidal, but as Lankford admits, “in many cases, human behavior is far too complex to be rigidly sorted into predetermined boxes” (p. 3). The decision of a suicide terrorist to sacrifice his or her life must be influenced by a combination of psychological, experiential, ideological, and circumstantial factors. Prediction will therefore be very difficult, and screening (such as Lankford suggests via computer tests in Nock et al. Reference Nock, Park, Finn, Deliberto, Dour and Banaji2010) virtually impossible. However, because suicide terror organizations require effective techniques to reinforce commitment, the range of typical group structures and practices associated with these organizations will tend to be narrower than that of the motivations of recruits. Profiling groups rather than individuals should be more effective in preventing future attacks.