Final Answer:
Mrs. Radley ran into the streets screaming because she witnessed her son Arthur Boo Radley placing a blanket around Scout Finch's shoulders. This unexpected and rare interaction with the outside world startled her causing an emotional outburst.
Step-by-step explanation:
Mrs. Radley's reaction can be traced back to the reclusive nature of the Radley family particularly Boo Radley. Throughout Harper Lee's To Kill a Mockingbird Boo is portrayed as a mysterious and elusive figure rarely seen outside the confines of the Radley house. The community speculates about Boo's behavior and his actions are often misunderstood. When Mrs. Radley saw Boo reaching out to interact with Scout it went against the established norms and expectations creating a moment of shock for her. This event disrupted the perceived order within the Radley household, prompting Mrs. Radley to express her distress through a public outburst.
Furthermore the symbolism of the blanket adds depth to the situation. A blanket is often associated with warmth comfort and protection. Boo's act of placing a blanket around Scout's shoulders suggests a rare and unexpected act of kindness. Mrs. Radley witnessing her son breaking free from his isolated existence to offer solace to another person experienced a mix of emotions—surprise confusion and perhaps concern for Boo's well-being. The unexpected nature of this encounter combined with the symbolic gesture overwhelmed Mrs. Radley leading to her running into the streets screaming.
In summary Mrs. Radley's reaction was a result of the startling departure from Boo Radley's usual behavior symbolized by the act of placing a blanket around Scout. The incident challenged preconceived notions about the Radley family evoking a powerful emotional response from Mrs. Radley which she expressed through her spontaneous and dramatic reaction in the streets.