Karen horney emphasized that childhood anxiety is caused by

Sense of helplessness

Explanation:

Karen Horney was a German psychoanalyst. She emphasized that childhood anxiety is most likely as a result of a sense of helplessness. She emphasized that the feeling of helpless and abandonment is what makes a child develop insecurity and hence results to what she called basic anxiety.

A child tend to be susceptible to anxiety when he/she is dependent oon a guardian or an authority figure for survival and sustenance (sense of helplessness)