When an ISFJ (Introverted, Sensing, Feeling, Judging) becomes angry, their behavior and demeanor can change significantly. Here is a detailed description of how an ISFJ may behave when angry:

1. Internalizing emotions: ISFJs tend to internalize their anger rather than expressing it outwardly. They may not immediately show their anger, but instead, keep it to themselves and ruminate over it internally. This can lead to a buildup of frustration and resentment.

2. Withdrawal: When angry, ISFJs may withdraw from social interactions and prefer to be alone. They may isolate themselves to process their emotions and regain their composure. During this time, they may become distant and unresponsive to others.

3. Passive-aggressive behavior: ISFJs are generally conflict-averse and may struggle to express their anger directly. Instead, they may resort to passive-aggressive behavior, such as giving the silent treatment, making sarcastic remarks, or engaging in subtle acts of defiance. They may also become overly critical or nitpick about minor issues.

4. Emotional sensitivity: ISFJs are highly attuned to their emotions and the emotions of others. When angry, their emotional sensitivity may intensify, making them more reactive to perceived slights or injustices. They may become easily hurt or offended, and their anger can be triggered by feeling unappreciated or taken for granted.

5. High expectations: ISFJs have a strong sense of duty and responsibility. When angry, they may become frustrated if others fail to meet their expectations or if they perceive a lack of effort or commitment. They may feel let down by those they trust and may struggle to understand why others do not share their values or work ethic.

6. Difficulty expressing anger: ISFJs may find it challenging to express their anger directly and assertively. They may fear confrontation or worry about damaging relationships. As a result, they may suppress their anger, leading to increased stress and internal turmoil.

7. Physical symptoms: When angry, ISFJs may experience physical symptoms such as tension headaches, stomachaches, or muscle tension. Their bodies may react to the stress and frustration they are feeling, even if they do not openly express it.

8. Need for resolution: ISFJs value harmony and seek resolution in conflicts. Once they have had time to process their anger, they may actively work towards finding a solution or restoring peace. They may be willing to engage in open and honest conversations to address the underlying issues and rebuild relationships.

It's important to note that individuals may vary in their expression of anger, and not all ISFJs will exhibit these behaviors. Additionally, healthy coping mechanisms and personal growth can help ISFJs manage their anger more effectively.