Which of the following describes negative effects of external environmental factors on social/emotional development?

The selection highlighting that external environmental factors can encourage aggression, anxiety, or depression effectively captures the negative impact that adverse surroundings can have on a child's social and emotional development. Factors such as living in a stressful home environment, experiencing trauma, or facing discrimination can lead to increased emotional distress. This distress often manifests as behaviors associated with aggression or heightened anxiety and can trigger depressive symptoms.

In contrast, the other options focus on positive outcomes. For instance, boosting attachment security and relationship building, supporting trust and emotional resilience, or promoting healthy interpersonal skills all reflect scenarios in which the environment is nurturing and supportive. Such positive environments can help with social and emotional growth, whereas negative environmental factors can hinder these processes and lead to detrimental outcomes. The essence of this option lies in acknowledging that certain external factors, especially when harmful or neglectful, may significantly impede a child's ability to develop healthy emotional and social skills.