Final answer:
Macbeth is immediately plagued by guilt and paranoia after Duncan's murder, while Lady Macbeth is composed and pragmatic, eventually descending into madness. Their contrasting behaviors highlight Macbeth's immediate breakdown and Lady Macbeth's delayed reaction.
Step-by-step explanation:
The behavior of Macbeth and Lady Macbeth after the discovery of Duncan's murder exhibits a stark contrast between the two characters. Macbeth is overwhelmed by guilt and paranoia, as seen in his hallucinations and the lines 'Methought I heard a voice cry 'Sleep no more! Macbeth does murder sleep', indicating that he is haunted by his action and believes he will never find peace or rest again. In comparison, Lady Macbeth displays pragmatism and a cold composure, scolding Macbeth for his weaknesses and trying to manage the situation by telling him to wash the blood off his hands and return the daggers to frame the guards.
Lady Macbeth's behavior reveals her attempts to maintain control and cover up the crime, as demonstrated when she faints strategically to divert attention away from Macbeth's erratic behavior after the murder is discovered. However, her stoic façade eventually collapses, culminating in her sleepwalking and revealing her own deep-seated guilt and descent into madness, echoing Macbeth's earlier guilt but occurring much later as her composure crumbles. Both characters ultimately succumb to guilt and madness, but they exhibit it in differing timelines and behaviors post-murder.