Can we tell whether you’re male or female? It’s a simple question, but the answer is often more complex than people expect. In many situations, we assume gender can be identified quickly from appearance, voice, or behavior. Yet those assumptions are not always accurate. The way we recognize sex or gender is shaped by biology, social cues, and personal identity, and these factors do not always align in obvious ways. Exploring this question reveals how easily first impressions can mislead us and why clear distinctions are not always possible. By looking more closely at what informs our judgments, we can better understand both the limits of perception and the diversity of human identity.