The hedgehog's dilemma, or sometimes the porcupine dilemma, is an analogy about the challenges of human intimacy. It describes a situation in which a group of hedgehogs all seek to become close to one another in order to share heat during cold weather. They must remain apart, however, as they cannot avoid hurting one another with their sharp spines. Though they all share the intention of a close reciprocal relationship, this may not occur, for reasons they cannot avoid.
''A number of porcupines huddled together for warmth on a cold day in winter; but, as they began to prick one another with their quills, they were obliged to disperse. However the cold drove them together again, when just the same thing happened. At last, after many turns of huddling and dispersing, they discovered that they would be best off by remaining at a little distance from one another.
In the same way the need of society drives the human porcupines together, only to be mutually repelled by the many prickly and disagreeable qualities of their nature. The moderate distance which they at last discover to be the only tolerable condition of intercourse, is the code of politeness and fine manners; and those who transgress it are roughly told - in the English phrase - to keep their distance. By this arrangement the mutual need of warmth is only very moderately satisfied; but then people do not get pricked. A man who has some heat in himself prefers to remain outside, where he will neither prick other people nor get pricked himself.''
Both Schopenhauer and Freud have used this situation to describe what they feel is the state of individuals in relation to others in society. The hedgehog's dilemma suggests that despite goodwill, human intimacy cannot occur without substantial mutual harm, and what results is cautious behaviour and weak relationships.
The dilemma is also used to justify or explain introversion and isolationism. The concept originates from Arthur Schopenhauer's 'Parerga and Paralipomena'. It then entered the realm of psychology after the tale was discovered and adopted by Freud in 1921.
Sometimes love can be a spiky situation.