Doctoral Dissertation Research in DRMS: Testing the Effects of Facial Sexual Dimorphism on Men’s Selective Attention, Implicit Association, and Decision Making

在人类互动中，脸是主要的注意力焦点。尽管人们发现不同人的脸很容易识别，但事实上，脸是高度可变的。面孔变化的一种方式是男性对女性的维度。男性化的脸比女性化的脸有更宽的下巴、更厚的眉脊和更长的下巴。研究表明，人们认为男性化的脸属于身体上更具支配力和攻击性的人。这些认知可能会影响日常生活中的决策，比如我们选择谁来领导组织或执行某些任务。虽然以前的研究有助于我们理解个人对支配地位的看法，但它并没有揭示他们这样做的原因。这个项目研究了不同的男性面孔是如何吸引注意力、影响记忆和影响对威胁的感知的。一种假设是，面部阳刚之气高的面孔被认为更具威胁性，这增加了他们的注意力和记忆力。这项研究的结果有可能让我们了解我们对面部感知的认知过程，并为开展未来的研究提供方法论基础，以理解为什么高度男性化的个体受到尊重。实验可以测试面部男性气质对观察者的支配和威胁感知的影响。然而，大多数测试操纵面部性别二态性对观察者感知影响的实验都依赖于强迫选择范式，这有明显的缺陷。目前的研究使用了一种改进的方法来检验人类的注意力自动优先处理男性面孔的假设，以及观察者对男性面孔的选择性注意是因为他们发出威胁的信号。这项研究的参与者是大学生。基本的实验范式让参与者完成自我报告的身体优势、状态和特质焦虑水平，以及他们的身体尺寸（身高、体重、握力和胸力）。这些措施，收集之前的实验，用于量化参与者的身体优势和焦虑，并在分析中作为协变量。参与者完成四个实验中的一个。Dot探针和侧卫任务都测试了参与者是否在没有指示的情况下选择性地关注男性化的面孔。在“点探测”任务中，研究人员向参与者展示了两张不同男性特征的脸，然后展示了一个目标形状，正方形或菱形。参与者必须尽可能快地对形状进行分类。在侧翼任务中，参与者判断目标字母的中心方向（即，直立或倒置），而忽略侧翼的男性面孔。词汇决策任务测试参与者是否自动将这些面孔与威胁概念联系起来。参与者判断一个字母串是否是一个单词，而忽略同时呈现的一张性别二态性不同的脸。字母字符串的一部分是与威胁概念相关的单词。当一个字母串是一个威胁词，并且呈现的脸被男性化时，参与者被认为是最快将其分类为单词的。在评定识别记忆测试中，研究人员向参与者展示了一组性别二态性不同的男性面孔，并要求他们对每个人的危险性进行评定。然后，参与者完成一个识别记忆阶段，在这个阶段，他们会看到另一组面孔，其中一些是在评价阶段出现的，并被要求判断他们是否在评价阶段看到了每张面孔。假设威胁刺激在初始编码时更为显著，对被认为更具威胁性的男性化面孔的更好记忆通过识别记忆任务进行评估。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Faces are the primary focus of attention during human interaction. Although humans find different people’s faces easy to recognize, faces are in fact highly variable. One way in which faces vary is on the masculine-to-feminine dimension. Masculine faces are those with broader jaws, thicker brow ridges and longer chins than feminine faces. Studies have shown that people rate masculine faces as belonging to more physically dominant and aggressive individuals. These perceptions may affect decision making in everyday life, such as who we choose to lead organizations or perform certain tasks. While previous studies have aided our understanding of individuals’ perceptions of dominance, it does not reveal why they do so. This project examines how faces differing in masculinity capture attention, affect memory, and impact perceptions of threat. A hypothesis is that faces with high levels of facial masculinity are perceived as more threatening and that this increases their attention and memory for them. Results of this research have the potential to inform our understanding of the cognitive processes which underlie our face perceptions and provide a methodological basis to conduct future studies to understand why highly masculine individuals are treated with deference.Experiments can provide tests of the effects of facial masculinity on observers’ dominance and threat perceptions. However, most experiments testing the effects of manipulating facial sexual dimorphism on observers’ perceptions have relied on forced choice paradigms, which have significant drawbacks. The current research uses an enhanced methodology to examine the hypothesis that human attention automatically prioritizes processing of masculine faces, and that observers’ selective attention to masculine faces is because they signal threat. Participants in the study are college students. The basic experimental paradigm has participants complete self-reported ratings of physical dominance, state and trait anxiety levels, and their body dimensions (height, weight, grip strength and chest strength). These measures, collected prior to the experiments, are used to quantify participants physical dominance and anxiety and serve as covariates in the analyses. Participants complete one of four experiments. Both the Dot Probe and Flanker Task test if participants selectively attend to masculinized men’s faces when they are not instructed to. For the Dot Probe task, participants are presented with two faces varying in masculinity, which is followed by the presentation of a target shape, either a square or diamond. Participants must classify the shape as quickly as they can. For the Flanker Task, participants judge the orientation of a centrally presented target letter (i.e., upright, or upside-down) while ignoring flanking faces varying in masculinity. The lexical decision task tests whether participants automatically associate these faces with the concept of threat. Participants judge whether a letter string is a word, while ignoring a simultaneously presented face varying on sexual dimorphism. A portion of the letter strings are words related to the concept of threat. Participants are assumed to be fastest to classify a letter string as a word when it is a threat word, and the presented face has been masculinized. In the rating recognition memory test participants are presented with a sequence of men’s faces varying on sexual dimorphism and asked to rate how dangerous each man appears. Participants then complete a recognition memory phase, in which they are presented with another sequence of faces, some of which were presented in the rating phase, and asked to judge whether they saw each face in the rating phase. Better memory for masculinized faces that are perceived as more threatening, assuming threat stimuli is more salient at initial encoding, is assessed with the recognition memory task.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.