Ishin-denshin (以心伝心?) originally comes from a Chinese proverb  and is a Japanese idiom which denotes the traditional concept of interpersonal communication through unspoken mutual understanding. This four-character compound, known as a yojijukugo, literally translates as "what the mind thinks, the heart transmits." Sometimes explained in English in terms of "telepathy" or "sympathy", ishin-denshin is also commonly rendered as "heart-to-heart communication" or "tacit understanding." Ishin-denshin is present in every society on Earth in the way people look at each other and go through a variety of nonverbal gestures peculiar to their nationality, ethnicity or shared cultural background. Learned non-verbal cues require a community or culture for their reinforcement; table manners are not innate capabilities upon birth. Human children’s skills of shared intentionality develop gradually during the first 14 months of life as two ontogenetic pathways intertwine, so the developmental outcome is children’s ability to construct dialogic cognitive representations, which enable them to participatet in human collective cognition.
Although silent understanding is generally recognized as a universal human phenomenon, the expression ishin-denshin is often used to describe this style of nonverbal communication between two people that is felt by some Japanese to be unique to the Japanese race. Whereas the Japanese concept of haragei denotes a deliberate form of non-verbal communication, ishin-denshin refers to a passive form of shared understanding. Ishin-denshin is traditionally perceived by the Japanese as sincere, silent communication via the heart or belly (i.e. symbolically from the inside, uchi), as distinct from overt communication via the face and mouth (the outside, soto), which is seen as being more susceptible to insincerities. Such concepts are related to the traditions of Zen, where the term ishin-denshin refers to direct mind transmission.
Ishin-denshin continues to influence many aspects of contemporary culture, ranging from business practices to end-of-life care. Research supports the view that Ishin-denshin is a mechanism for norm regulation that does not rely on explicit information exchange or costly reinforcement, but rather on the sensitivity of group members to social cues in their environment which can signal a threat to one’s inclusionary status in the group and (as in Japan) motivate people to shift their attitudes to be in line with group social norms.
Western need for clarity in interpersonal communication are often described as repellent by Japanese people who believe themselves more accustomed to ishin-denshin and implicit rather than explicit forms of understanding.
- De Mente, Boyé Lafayette (1994). Japanese Etiquette & Ethics In Business. McGraw-Hill Professional. p. 165. ISBN 978-0-8442-8530-6. Retrieved July 28, 2012.
- Cheung, King-Kok (1993). Articulate Silences: Hisaye Yamamoto, Maxine Hong Kingston, Joy Kogawa. Cornell University Press. p. 146. ISBN 978-0-8014-8147-5. Retrieved 29 July 2012.
- Pulvers, Roger. "Japanese betray some blinkered views of their foreign coworkers" Japan Times, July 4, 2010, p. 8.
- Tomasello, M.; Carpenter, M.; Call, J.; Behne, T.; Moll, H. (2005), "Understanding and sharing intentions: The origins of cultural cognition", Behavioral and brain sciences 28 (5): 675–690
- Davies, Roger J.; Ikeno, Osamu (March 15, 2002). The Japanese Mind: Understanding Contemporary Japanese Culture. Tuttle Publishing. pp. 52–54, 105. ISBN 978-0-8048-3295-3. Retrieved July 28, 2012.
- Baroni, Helen Josephine (2002). The Illustrated Encyclopedia of Zen Buddhism. The Rosen Publishing Group. p. 156. ISBN 978-0-8239-2240-6. Retrieved July 28, 2012.
- Okuno, S.; Tagaya, A.; Tamura, M.; Davis, A. J. (1999). "Elderly Japanese people living in small towns reflect on end-of-life issues". Nursing ethics 6 (4): 308–315. PMID 10696179.
- Slingsby, Brian Taylor (2005). "The nature of relative subjectivity: a reflexive mode of thought". The Journal of Medicine and Philosophy 20 (1): 9–25. doi:10.1080/03605310590907039. PMID 15814365. Retrieved July 28, 2012.
- Koudenburg, Namkje; Postmes, Tom; Gordijn, Ernestine H. (2013), "Subtle Norm Regulation in Everyday Interactions", Social Psychology Quarterly 76 (224): 241
- De Mente, Boyé Lafayette (September 2006). Business Guide to Japan. Tuttle Publishing. pp. 28–32. ISBN 978-0-8048-3760-6. Retrieved 29 July 2012.