What is why is the oldest child the ugliest?

It's important to note that the idea of the oldest child being the "ugliest" is a stereotype and not based on scientific evidence or fact. Attributing physical appearance qualities to birth order likely stems more from social perceptions and family dynamics rather than genetic or biological factors. Here are a few points to consider:

1. Perception Over Reality: Beauty and attractiveness are highly subjective and influenced by cultural, societal, and personal preferences. What one person considers attractive, another might not, regardless of birth order.

2. Personality and Behavior: The oldest child often takes on leadership roles and may be seen as more responsible or authoritative, which could affect how their appearance is perceived in terms of seriousness or maturity, rather than physical beauty.

3. Psychology and Stereotypes: Stereotypes about birth order can influence perceptions. Common characterizations of oldest children as more serious or stressed might inadvertently be linked to physical perceptions due to their often assumed role in the family.

4. Family Dynamics: In terms of attention and resources, the first child receives undivided parental attention at first but may face more expectations and scrutiny as they grow, which can influence their self-image and how others perceive them.

5. Individual Differences: Every child is unique regardless of birth order. Genes, environment, upbringing, and individual experiences contribute to the development of a person's appearance and personality.

In essence, attributing appearance to birth order lacks scientific grounding and varies greatly between individuals and families. It's more productive to appreciate each person for their unique qualities and attributes.