Psychology is an area of science that studies how people think, feel and behave. To do so, psychologists study the human brain, and biological, and physiological processes in the body, as well as socio-environmental-spiritual and cultural processes that influence and are influenced by our thoughts, emotions and feelings. Some of these processes include intelligence, memory, perception, attention, executive functions, motivation, modelling, learning, culture, beliefs, family and trauma history.
 
Child, adolescent, and family psychology are specialties within psychology.
Here is a brief summary of what they are:
 
Child and adolescent psychology focuses on studying how humans develop and adapt their ways of learning, interacting with others, thinking, feeling, and behaving to and in their environment from an early age to form their personality later in life. Sometimes, in this process of developing physically and psychologically and adapting to their environment, some children and adolescents develop what we call mental health issues. For example, issues linked to how their brain develops (e.g., neurodevelopmental disorders such as ADHD, ASD) and how their body works, or how their brain responds to other people, substances, and circumstances of their environments (e.g., anxiety, depression, worries, addiction, behavioural problems, emotion dysregulation). Mental health issues may interfere with a person’s ways of thinking, feeling and behaving as well as with their functioning in everyday life, society, school and learning for as long as the issues remain untreated. Mental health and developmental needs can be difficult to identify in children and adolescents because they often go unnoticed when they start but become more obvious gradually, as children age. This happens because of the expectations that become more complex with time across different areas of life such as school, home, social, and learning. Whether it is a mental health issue or a specific need, the correct assessment and treatment from a psychologist can help children, adolescents and families understand, manage and improve their thinking, emotions and behaviours. 

 Family/parenting psychology is the study of how people develop and learn to interact and trust themselves and others in specific environments. Overall, the ways people interact with themselves and one another are learned from an early age (i.e., attachment styles) and then replicated across life, but they are also influenced by how people think, feel and behave in the moment as well as their physical and psychological health. After people have interacted with each other a few times, they often form their relationship style. This applies to any relationship: parent-child, siblings, friends, partners, couples. However, in many cases, the relationship style may cause people to suffer and wish things were different and they could connect more positively with one another. For parents, their style of interaction with their children determines how easier or more difficult parenting will be for each parent/carer. Four aspects impact parent-child interaction: 1- Their life/family/support circumstances of the present time and resources available (i.e., "it takes a village"), 2- Their own emotion regulation skills, which are being modelled for the child, 3- Their knowledge of child development and behaviour management skills, 4 - Their pattern of interaction growing up with their parents/carers. Psychologists use family and parenting interventions to dive deep into understanding people's relationship styles and supporting them in developing awareness and learning specific strategies and skills towards building more positive and healthy ways to interact and communicate within their family.