What is Psychology?
Psychology is the science that systematically studies human behaviour, thought and emotion, as well as the biological, psychological and social factors that shape them. It is an independent science, although many of its branches overlap with other disciplines: Clinical Psychology with Psychiatry, Social Psychology with Sociology, and Biopsychology and Neuropsychology with Biology and Neuroscience.
A brief history of the science
Like many sciences, psychology has its roots in philosophy. It is considered to have acquired an independent scientific identity from the mid-19th century, with Wilhelm Wundt’s establishment of the first experimental psychology laboratory in Leipzig (1879). Since then, the science has passed through successive movements: Sigmund Freud’s Psychoanalysis, Behaviourism and, from the 1950s onwards, the “cognitive revolution”, which placed mental processes (memory, perception and thought) at the centre of attention. The Cognitive-Behavioural approach (CBT), which emerged from this convergence, is now one of the therapeutic approaches with the strongest research evidence.
Psychology today: neuroscience, positive psychology and evidence-based practice
In recent decades, the integration of neuroscience (brain imaging and genetics) has led to biopsychosocial models for understanding human behaviour. Newer approaches have also developed, such as Evolutionary Psychology and Positive Psychology, which focuses on individuals’ wellbeing, strengths and resilience rather than solely on psychopathology. At the same time, since 2011, the scientific psychology community has undergone a substantial process of self-examination and reform (known as the “replication crisis”), which has led to more rigorous research standards: preregistration of studies, open data and larger samples — standards that are now the norm in reputable scientific journals. A large-scale attempt to replicate 100 psychology studies (Open Science Collaboration, 2015, in the journal Science) found that only 36% of the results were replicated with statistical significance, a finding that prompted substantial reforms in how research is conducted today.
Modern clinical practice is now based on the principle of “evidence-based practice”, as formally defined by the American Psychological Association (APA Presidential Task Force on Evidence-Based Practice, 2006): combining the best available research evidence, the practitioner’s clinical expertise and the individual’s needs and values, rather than adhering exclusively to a single theoretical “school”.
Branches of Psychology
Today, psychology includes many specialist branches, such as Clinical Psychology, Social Psychology, Cognitive Psychology, Developmental Psychology, Health Psychology, School/Educational Psychology and Neuropsychology. Each studies behaviour from a different perspective, with the shared aim of understanding and improving human quality of life.
Psychology in Greece
In Greece, academic psychology developed relatively recently compared with other countries. The first independent Department of Psychology was established in 1987 at the University of Crete (Rethymno). Panteion University and the Aristotle University of Thessaloniki followed in the 1990s, while the programme at the National and Kapodistrian University of Athens evolved into an independent Department of Psychology in 2013. In recent years, additional Departments of Psychology have been established at the University of Ioannina, the University of Western Macedonia (2019) and the Democritus University of Thrace (2023), bringing the number of public Departments of Psychology in Greece to seven: Panteion University, Aristotle University of Thessaloniki, National and Kapodistrian University of Athens, University of Ioannina, University of Western Macedonia and Democritus University of Thrace.
How psychology is applied in practice
Research methods in psychology
As an empirical science, psychology draws its conclusions from systematic research rather than simple observation or intuition. The main research methods include the experiment (in which the researcher manipulates variables to examine causal relationships, usually with a control group and randomisation), the correlational study (which examines relationships between variables without establishing causation), the case study (an in-depth analysis of an individual or a small group), and longitudinal studies (which follow the same individuals over an extended period, for example in developmental psychology). The choice of method depends on the research question: a correlation does not establish causation (“correlation is not causation”), a fundamental principle when evaluating any psychological study.
Ethics in psychological research
Research involving human participants is governed by strict ethical rules, as described in the American Psychological Association’s (APA) “Ethical Principles and Code of Conduct”. Every research study must ensure participants’ informed consent, protect the confidentiality of their data, allow them to withdraw at any time without consequences, and minimise any psychological or physical burden. Most studies today are reviewed in advance by university ethics/bioethics committees before approval is given for them to proceed.
Theoretical knowledge in psychology is put into practice through Counselling and Psychotherapy, as well as through the profession of psychology itself, which is governed in Greece by a specific legal and ethical framework.
References
Open Science Collaboration. (2015). Estimating the reproducibility of psychological science. Science, 349(6251), aac4716. https://doi.org/10.1126/science.aac4716
APA Presidential Task Force on Evidence-Based Practice. (2006). Evidence-based practice in psychology. American Psychologist, 61(4), 271–285. https://www.apa.org/practice/guidelines/evidence-based-statement
American Psychological Association. (2017). Ethical principles of psychologists and code of conduct. https://www.apa.org/ethics/code