Collaborative Research: Psychological and Behavioral Preparatory Responses to Male Aggressive Vocal Signaling

人身攻击有严重的后果，但往往开始于看似微不足道的口头争端（“我不喜欢你的语气”）。这些言语冲突在熟人和陌生人之间都很常见。其中一些冲突很快以一方退出而告终，但另一些冲突则升级为口头上的肢体冲突，甚至是致命的打斗。在决定一场口头争执是否会演变成一场打斗时，声音品质（不是人们说什么，而是声音的物理方面）扮演着什么样的角色？对其他动物的研究表明，声音品质通常提供有关体力和攻击意图的信息，这些信息可以预测战斗结果，从而影响个体的战斗动机。例如，先前的研究表明，声音低沉的男性被认为比声音不那么低沉的男性更有可能赢得斗殴。在这种情况下，音高是一种操纵“信号强度”的方式，进化理论认为这将传达对潜在攻击者有用的重要线索。 一个强信号传达说话者更有动机去攻击，或者比一个弱信号更强壮。理论表明，听者的撤退或攻击的可能性应该受到对声音的感知的影响，但研究尚未在人类身上测试这些假设。因此，这个项目建立在以前关于感知声音的发现的基础上，将其扩展到人们对攻击的准备。研究人员通过实验来创造温和的竞争环境，并研究信号说话者的声音特征是否会影响听者的攻击倾向。了解声音品质如何减少或增加攻击性将有助于经常接触暴力的专业人士（例如，警察）导航危险，并通知干预计划，旨在减少暴力。恩奎斯特的报复成本模型，动物攻击性交流的主要模型。研究人员将测量人们对声音特征的心理和身体反应，这些声音特征是攻击意图或攻击能力的强或弱信号。在三组实验中，研究人员将操纵男性说话者声音的信号强度是强还是弱。实验集1还操纵说话者的面部优势，以及他表达愤怒的主题是否具有重要或最小价值。三个操纵变量的交互作用会影响听者对攻击意图的判断。实验二将测试听者的体力和配偶竞争的线索如何影响他们对说话者的注意和记忆。实验组3通过关注听者的攻击性思维和准备（例如，立即增加体力）以响应强强度与弱强度的听觉信号。为了提高项目的有效性，调查人员将招募警察参与实验组1。为了促进跨文化比较，研究人员将在中国进行平行实验，中国的杀人率比美国低得多。

Personal aggression has serious consequences yet often starts with seemingly trivial verbal disputes ("I don't like your tone"). These verbal conflicts are common between both acquaintances and strangers. Some of these conflicts quickly end with one party standing down, but others escalate verbally to physical, even fatal, fights. What role do vocal qualities (not what people say, but physical aspects of the voice) play in determining whether a verbal dispute becomes a fight? Research on other animals indicates that vocal qualities often give information about physical strength and aggressive intentions, which can predict fight outcomes and thus affect an individual's motivation to fight. For example, previous research shows that men with lower pitched voices are judged as being more likely to win fistfights than men with less deep voices. In this case, pitch is a way to manipulate "signal intensity", which evolutionary theory suggests would convey important cues useful to a potential attacker. An intense signal conveys the speaker is more motivated to aggress or is physically stronger than would a weaker signal. Theory suggests that the listener's likelihood of retreating or attacking should be affected by perceptions of the voice, but research has not yet tested those hypotheses in humans. Thus this project builds on previous findings about perceiving voices, to extend it to people's preparation to aggress. The investigators use experiments to create mildly competitive situations and examine whether signal speaker's vocal features affects listeners' aggressive inclinations. Understanding how vocal qualities can reduce or increase aggression will help professionals who are regularly exposed to violence (e.g., police officers) to navigate danger, and inform intervention programs that aim at curtailing violence.This project tests key hypotheses drawn from M. Enquist's retaliation-cost model, a leading model of aggressive communication in animals. The investigators will measure people's psychological and physical responses to vocal features that serve as strong or weak signals to aggressive intent or aggressive ability. In three sets of experiments, the investigators will manipulate whether the signal intensity of a male speaker's voice is strong or weak. Experiment Set 1 also manipulates facial dominance of the speaker, and whether the topic of his expressed anger is of significant or minimal value. Interactions of the three manipulated variables are predicted to affect listener's judgments about aggressive intent. Experiment Set 2 will test how listeners' physical strength and cues of competition for mates influence their attention to and memory of the speaker. Experiment Set 3 extends the Set 2 by focusing on listeners' aggressive thinking and preparation (e.g., immediate increases in physical strength) in response to hearing signals of strong versus weak intensity. To enhance the validity of the project, the investigators will recruit police officers to participate in Experiment Set 1. To facilitate cross-cultural comparisons, the investigators will perform parallel experiments in China, a country with much lower homicide rates than the U.S. This project will provide a deeper understanding of the evolution and function of voice pitch in aggressive interactions.