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，人脸是人们关注的主要焦点。尽管人类发现不同的人的脸很容易辨认，但实际上面孔的差异很大。面孔变化的一种方式是从男性到女性。男性面孔是指那些下巴更宽、眉脊更粗、下巴更长的人。研究表明，人们认为男性面孔属于身体更强势、更具攻击性的人。这些认知可能会影响日常生活中的决策，例如我们选择谁来领导组织或执行某些任务。虽然之前的研究帮助我们理解了个人对支配地位的认知，但它并没有揭示他们为什么会这样做。这个项目考察了男性气概不同的面孔如何吸引注意力，影响记忆，并影响对威胁的感知。一种假设是，面部男子气概水平较高的面孔被认为更具威胁性，这会增加他们对自己的注意力和记忆力。这项研究的结果可能会让我们了解构成我们面部感知的认知过程，并为未来进行研究提供方法论基础，以理解为什么高度阳刚的人会受到区别对待。实验可以测试面部男子气概对观察者的优势和威胁感知的影响。然而，大多数测试操纵面部性别二态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这样一种假设，即人类的注意力自动优先处理男性面孔，而观察者对男性面孔的选择性关注是因为它们发出了威胁的信号。这项研究的参与者是大学生。基本的实验范式让参与者对身体优势、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)进行完整的自我报告。这些测量是在实验前收集的，用来量化参与者的身体优势和焦虑，并在分析中充当协变量。参与者完成四个实验中的一个。如果参与者在没有被指示的情况下选择性地注意到男性的脸，那么点探测器和侧翼任务都会测试他们。在Dot Probe任务中，参与者会看到两张男子气概不同的脸，然后是一个正方形或菱形的目标形状。参与者必须尽快对形状进行分类。在侧翼任务中，受试者判断一个居中呈现的目标字母的方向(即，倒立或倒置)，而忽略不同男性气概的侧翼面孔。词汇判断任务测试参与者是否自动将这些面孔与威胁概念联系在一起。参与者判断一个字母串是否是一个单词，而忽略了同时呈现的一张性别不同的面孔。字母串的一部分是与威胁概念相关的单词。当字母串是威胁词时，假设参与者最快将其分类为单词，并且呈现的面孔已被男性化。在等级识别记忆测试中，参与者看到了一系列性别不同的男性面孔，并被要求对每个男性看起来有多危险进行评级。然后，参与者完成识别记忆阶段，在这个阶段，向他们展示另一系列人脸，其中一些是在评级阶段呈现的，并要求他们判断他们是否在评级阶段看到了每一张脸。通过识别记忆任务评估被认为更具威胁性的男性化面孔的更好记忆，假设威胁刺激在初始编码时更加突出。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.