Two or more characters (frequently twins) are in such perfect harmony that they seem almost to be one person with two bodies. They finish each other's sentences, never seem to need to talk to communicate, and may even know what is happening to each other from far away.
In Sci-Fi or Fantasy series, the connection may actually be a true shared mind, either with each individual member contributing to the whole (while retaining their own bodies), or the separate bodies being expendable proxies which the Hive Mind controls. It makes sense that the first variant is usually sensitive to losses and avoids overt violence, but in the second, it's only the question of whether lost bodies will be replenished in its quest to expand itself. Expect the drones of such hive minds to be considered very killable by everyone else as well. It is not unusual for a hive mind to start out as the former and then slip into the latter as a series progresses and the writing staff changes. The Virus is often a Hive Mind (e.g., the Borg) and the Evil Matriarch becomes its Hive Queen.
There is a traditional tendency in SF and fantasy shows for Hive Minded species to be xenophobic, aggressive, and evil, even when they aren't a Horde of Alien Locusts. This may well be due to a perceived metaphorical overlap with Dirty Communists (even when a Hive Queen is present, which would technically make them a caste system), or a residual, primal fear relating to eusocial insects, which are the closest thing to Hive Minds in Real Life. It could be justified, however, as it's possible that a truly hive-minded species may literally never encounter another sentient entity until it achieves interstellar travel, and so have a distinct lack of social skills. If a normally individual species turns into a hive mind, they might use social skills less often and deem being hive-minded as superior (therefore, having disdain for individualists who don't want to join their Hive Mind). This trope is particularly common among transhumanist works, however, where an advanced level of technology is assumed. They may wish for you join them and refuse to take no for an answer — not realizing/caring that we enjoy our individuality.
Hive minds are not known to exist in reality — hive-dwelling insects, from which the phrase is derived, communicate intentions and commands through scent and body language but possess individual minds. The closest approach to them would be the controversial superorganism👁 Image
concept. However, it should be noted that a somewhat rough form of this does occur in humans presently: the advent of the internet in the early 90's not only enabled the instantaneous transfer of global information and knowledge to the point that many people, even swaths of strangers are able to communicate and share their information rather rapidly in modern society and you'd be hard-pressed to find a corner of the Earth connected via the Web that would ignore another group or individual's suffering upon it being posted online, even if that person(s) isn't even remotely or tangentially related to them. Slower and more historical versions have included any group of people, particularly larger, long-lasting groups. Big companies and organizations, for instance, may well have 'minds' based on evolved shared culture and methodologies passed down to new employees/members, and partially operate in ways that even their owners/CEOs are not necessarily fully aware of. This can lead to issues when a new leader wants to make changes, or to an inability to adapt gracefully to external changes.
Typically the group it consists of can be classified as The Hive, as the name suggests, though not all examples of a Hive have a Hive Mind, and vice versa; many Hive Minds are too individualistic for that, and most examples of The Hive don't actually have this kind of universal connection. Most are led in a more top-down manner (often by a single individual), or are largely instinct-driven. Note also that in cases where both tropes apply, The Hive is the faction, and the Hive Mind is the thing that unites said faction. Related to, but separate from Synchronization, where each individual experiences what the other does without necessarily being in rapport with each other. A Sub-Trope of Our Clones Are Different if the hive is made up of identical individuals. Contrast both Mind Hive and Many Spirits Inside of One, both its complete opposites, when multiple minds or Split Personalities are sharing one body (differentiated by the level of accord between them and/or their "host"); and Pieces of God, where a Cosmic Entity is split into several pieces, which may or may not be living entities themselves. May have a Hive Queen, which serves as the titular keystone of a Keystone Army of Hive Drones. See also Psychic Link for other connections between minds. A related plot is The Evils of Free Will. Compare Split-Personality Merge, where two or more Split Personalities become one. When the person speaks in plural, see I Am Legion. If the hive mind is controlling many smaller creatures that forms the shape of a larger creature, you may be dealing with The Worm That Walks.
See Mental Fusion for the comparatively less identity-diluting and usually temporary version.
A conscious goal of This Very Wiki. (See also Edit Tip #1.) On this wiki, you will often see this term used as a nickname for the TV Tropes community, especially our collective power to invoke the Wiki Magic.
Not to be confused with the book series by Janet Edwards or the YouTube channel.