It is unlikely for someone to develop Post-Traumatic Stress Disorder (PTSD) solely from witnessing arguments between their parents or siblings. PTSD typically results from exposure to a traumatic event that involves actual or threatened death, serious injury, or sexual violence, which overwhelms an individual's ability to cope with the experience.
While witnessing ongoing conflict within the family can be distressing and may lead to emotional difficulties, it is not typically classified as a traumatic event in the sense required to develop PTSD. However, it is essential to note that prolonged exposure to chronic stress, conflicts, or abuse within the family environment can have adverse effects on a person's mental health and well-being, even if it does not meet the criteria for PTSD.
It is important to seek support and resources if you or someone you know is experiencing distress or difficulty coping with family-related conflicts. Speaking with a mental health professional can be helpful in understanding and addressing any emotional challenges stemming from family dynamics.