Sisu is a Finnish concept described as stoic determination, the tenacity of purpose, grit, bravery, resilience, and hardiness.

It is generally considered not to have a literal equivalent in English but likely a cognate of Indian term vīrya derived from Avestan Verethragna meaning “smiting of resistance“.


Sisu is a form of courage that is presented typically in situations where success is against the odds.

It expresses itself in taking action against the odds and displaying courage and resoluteness in the face of adversity, in other words, deciding on a course of action and then sticking to that decision, even despite repeated failures. It is in some ways similar to equanimity, with the addition of a grim kind of stress management.

Gutsy” is a fairly close translation that uses the same metaphor (found in more languages than Finnish and English), as the word derives from sisus, which means “interior” and “entrails, guts“.

A concept closely related to sisu is grit, which shares some of its denoting elements with it, save for “stress management” and passion for a long-term goal.

Sisu may have an element of passion but it is not always present, unlike in the case of grit as defined by Dr. Angela Duckworth.

As a psychological capacity

Sisu is a term which dates back hundreds of years and is described as being integral to understanding Finnish culture.

It is a term for going beyond one’s mental or physical capacity and is a central part of the country’s culture and collective discourse.

However, hardly any empirical research has been done to explore the meaning of this construct as a possible psychological strength resource, and it has long seemed to have a somewhat elusive nature.

It has been usually studied as a cultural component among Finns and Finnish Americans, but as a psychological construct has remained under-researched and poorly defined.

As early as the 1940s, attempts were made to grasp the essence of it. The Finnish newspaper Uusi Suomi reached out to its audience for their definition of sisu and conducted a contest. Uusi-Suomi wrote:

“All of us somewhat know what sisu is … [it] has for long been a topic for discussion here in Finland and abroad. But how do we describe and define what sisu really is?”.

The quest for putting the essence of sisu into a definitive form has evidently been around for almost a century. More recently, William R. Aho, professor emeritus of sociology at Rhodes College, raised questions about it and stated that:

“we need a good deal of organized, systematic scientific research to discover the scope and depth of sisu, geographically and situationally, and the depth and strength of both the beliefs and behaviors surrounding and emanating from sisu.”

A study aimed to fill in that gap, and offer a more precise language for discussing the term. While examining sisu within the psychological framework, it sought to render it less elusive as a construct by giving it an easily citable definition rooted within the field of positive psychology.

Sisu as a psychological power potential was introduced for the first time in the 3rd World Congress on Positive Psychology in Los Angeles on 29 June 2013.

In the study, it is described as a psychological key competence which enables extraordinary action to overcome a mentally or physically challenging situation.

Sisu also contributes to what has been named the action mindset; a consistent, courageous approach toward challenges which at first seem to exceed our capacities.

A related online survey (conducted between March and May 2013) tracked the cultural representations of sisu among contemporary Finns (and Finnish Americans) and revealed that sisu is still deeply valued and that there is public interest for cultivating this strength capacity as well.

All in all, the study received 1,060 responses. Among the main findings was the perception of sisu as a reserve of power, which enables extraordinary action to overcome mentally or physically challenging situations (rather than being the ability to pursue long-term goals and be persistent).

To elaborate on the function of sisu: it is a powerful psychological potential which enables the individual to tap into mental strength beyond their pre-conceived resources. Wielding sisu in the face of adversity helps individuals push through what first seemed like the boundaries of their mental or physical capacities.

Furthermore, it is an action mindset which equips the individual to choose to take on challenges beyond their observed capacities. It provides the final empowering push when we would otherwise hesitate to act. Sisu can be conceptualized as taking action against the odds.

Additionally, even though 53% of the respondents believed some people innately have more sisu, a majority of 83% of the respondents believed that sisu is a flexible quality which can be cultivated through conscious practice (rather than a being a fixed quality), and the majority of respondents were interested in developing this capacity.

Sisu is not always an entirely positive quality.

In Finnish, pahansisuinen literally translated means one possessing bad sisu, a description of a hostile and malignant person.

Furthermore, the answers from the sisu survey indicate that there can be too much sisu, and according to the survey answers this leads to bull-headedness, foolhardiness, self-centeredness, and inflexible thinking. The study suggests that sisu should be informed by reason and cultivated (and practiced) with self-compassion.

Like any trait or psychological capacity, sisu is the complex product of genetic, psychological, biological and social factors, and its comprehensive understanding will require studies from multiple scientific perspectives.

Finland may have the initial monopoly on it as a cultural construct, but it is a universal capacity and the potential for it exists within all individuals.

The transformative power of narrative is widely acknowledged Through the process of social transfer of narratives, values become embedded within a culture and connected to the thought processes of its individuals.

People, through their choices and actions, bring these narratives to life in a dynamic process which can prime the behavior of an entire nation. Fostering sisu may very well be embedded in such behavior, rather than being a genetical trait which one is born with.

Sisu is a new term in the field of positive psychology, and it may contribute to our understanding of the determinants of resilience, as well as of achievement and the good life.

It is suggested that positive psychology research could benefit from focusing future interest on the unique cultural resource of sisu that individuals across the globe can leverage; as well as actively examining relevant constructs from other cultures.

*This article was originally published at