According to the theory of mind, we have the capacity to feel other people’s reality or experiences, and ‘to put oneself in another’s shoes’. As researchers, we study twins from various points of view, such as their anthropometric measures, cognitive and behavioral characteristics, and health, as well as numerous of other phenotypes. But do we really understand what is it to be an identical twin? What it is like to spend the very first days of life with someone exceptionally similar to oneself in many respects? Or to celebrate every birthday and experience every milestone with said person, while also being compared with him or her? What is this intersubjective dimension of thoughts, feelings and emotions that is extremely unique to twins? It is something very different to just seeing yourself in the mirror. A twin is another person, someone with whom one can talk, share thoughts, endure life’s difficulties and just be oneself, as Joleen Loucks Greenwood describes in her book, Identical Twins: Adult Reflections on the Twinship Experience.

The twin experience itself is exceptional; the story of even just one twin pair merits its own literary piece. However, the basis of this book is to fully investigate and attempt to understand the personal experiences of 113 identical twins of different ages and stages of life.

In her book, Joleen reflects on those questions that are of true concern for twins, but not often taken into consideration by others. For instance, how does this rare occurrence of twinship influence, first of all, the twins’ relationships with others — friends, other siblings and partners? Insight into the closeness — and also the strain of a twin pair’s relationship that appears when the twinship connection is somehow changed (i.e., by external circumstances or other people’s inclusion in the particular dyad) — is provided by many participants in different stories. By analyzing these stories, Joleen attempts to classify and systemize the twinship experience while also synthesizing its essence. Thus, readers will find many direct citations from interviews with twins throughout the book; however, at the same time, the author groups the answers and defines the twinship experience, sometimes with the help of twin ‘jargon’ in order to catch the intangible (e.g., ‘best friend’ with respect to the twin, ‘second fiddle’ or ‘third wheel’ with respect to people outside of the twin dyad, ‘striving for identity/individuality’). Joleen also discusses some phenomena, such as the ‘buffering effect’ from a specific twin position (i.e., the search of additional sources of support in a twinship to aid in coping with a stressful event) and the semantic analysis of words used by twins (e.g., ‘never alone’, ‘always’, ‘we’ instead of ‘I’, ‘unconditional love’). However, Joleen notes that the twinship experience can have different periods of togetherness, of sharing relationships with friends, siblings and partners, of distance or separation and even of losing one half of the twin pair. Taking this all into consideration, it is clear that through her book, Joleen captures the dynamic nature of twinship relationships.

The fact that the author is an identical twin herself makes the description more animated and provides a unique look into the intimate world of twins, as it brings in a more personal perspective that makes the text more sincere, and I would also say more vulnerable — you can feel the nerve of the invisible connection between two people brought into the world together.

All of these make reading Identical Twins feel as though it is exciting storytelling and convey the experience of what it is like ‘never to be alone’. So, although the book is recommended to twin researchers, educators, social workers and psychologists, it is also relevant to a wider readership, including those who are interested in reflections on life through exceptional personal experience. After all, we understand ourselves better through understanding the similarities and differences between others.