![]() ![]() At the same time, because body weight is almost impossible to fake, stags' roars also constitute an “unfakeable” index signal of RHP ( Maynard Smith and Harper, 2003). As such, an energetic cost proportional to signalers' condition prevents weaker stags from faking greater RHP, and the honesty of roaring rates as an RHP signal is maintained (i.e., the handicap principle Zahavi, 1975). Stags in worse conditions may be able to roar faster than its condition allows, but this cannot last long and will quickly exhausts the stags, impairing their ability to make the next move. Importantly, only stags in better physical conditions can roar faster because roaring fast is energetically demanding. With all else being equal, stags that are in better conditions and/or heavier are more likely to win physical fights. Stags' roars are an RHP signal because the roaring rate correlates with stag's physical condition (e.g., deterioration caused by aging Clutton-Brock and Albon, 1979) and the minimum formant frequency of the roars correlates with stags' body weight ( Reby and McComb, 2003). The roaring contests can resolve conflicts of interest because stags' roars convey information predictive of their chance of winning a pending fight against each other, and stags use such information to make fight-or-flight decisions. This is partly because roaring contests, where two stags stand apart from and take turn to roar at each other, resolve ~50% of the fights on average ( Clutton-Brock and Albon, 1979). However, the annual rate of permanent injuries is ~6% among stags that engage in rutting fights ( Clutton-Brock et al., 1979). For example, adult red deer stags weigh ~330 pounds on average and carry large, piercing antlers, and both features are capable of causing serious physical damages. Both types of aggressive signals are prevalent in animals (see below), and the use of those signals helps reduce the cost of combats. Aggressive SignalsĪggressive signals are naturally-selected structures or acts that communicate signalers' threat potential, including their resource-holding potential (RHP e.g., physical strength) and aggressive intent (i.e., the willingness to escalate in a fight Hurd and Enquist, 2005). This is because (to our knowledge) a major component of this opinion piece, namely aggressive-intent signaling, has been mostly demonstrated with vocal signals. At the same time, though this opinion piece concerns the signaling function of face, we use research on vocal signals to build up our arguments. In our discussion, we focus on men because interpersonal aggression is primarily a male activity ( Puts, 2010). We believe that these two hypotheses complement each other to provide a more complete analysis of the signaling function of the anger face. (2014) argued that the anger face communicates the angry person's commitment to carry out threats. In a paper published in the same year, Reed et al. (2014) argued that the anger face mainly enhances facial cues of physical strength, thereby increasing the angry person's perceived fighting ability. That is, what does the human anger face communicate? Given these species-typical features, recent studies sought to reveal their signaling function. This expression typically entails simultaneously lowering one's browridge, raising the cheeckbones and mouth, widening the nose, and pressing the lips ( Ekman and Friesen, 1978 Sell et al., 2014). Anger is an integral part of interpersonal aggression ( Baumeister et al., 1990 Sell et al., 2009b) and has a cross-culturally recognizable facial expression ( Ekman, 1973). ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |