A generic diagram of a human chemical bond, the two parallel lines indicative of the force that holds a pair in a relationship.
In human chemistry, human chemical bond, A≡B, is an electromagnetic induced stabilizing, attractive-to-repulsive, field-particle mediated, cohesive force functioning to hold human molecules (people) together into bound-state entities, such as marriage pairs, friendships, work units, and social collectives, etc. [1]

Overview
In 1910, American philosopher Mary Mesny outlined an early affinity bond and valence bond model of chemical bonding between human molecules or of human relationship attachment affixed in terms of atomic valency:

“Each human molecule has various bonds of affinity, satisfied, and unsatisfied. If his bonds of affinity are not met by the affinities of some other molecule, he is apt to be a very unstable chemical.”

Mesny's description of affinity bonds and also of "valence bonds" existing between humans or human molecules in combined relationships was an early statement of human chemical bonding theory, being that valence bond theory, an 1850s theory, soon became quantum mechanical bonding theory (c.1920s), and affinity bonding theory, a 1775 theory, soon became free energy bonding theory (c.1950s). [8] Thermodynamically, in modern terms, chemical bonding, human or otherwise, is determined according to free energy interactions. This logic is explained by American-born Canadian biochemist Julie Forman-Kay, in her 1999 article "The 'Dynamics' of the Thermodynamics of Binding", as such: [3]

“Whether two molecules will bind is determined by the free energy change (ΔG) of the interaction, composed of both enthalpic and entropic terms.”

The definition given here by Forman-Kay, to note, is defined in the context of interactions between protein molecules. The first to extrapolate this logic of free energy determined binding to the case of interactions between human molecules, was American chemical engineer Libb Thims in circa 2005, in his evolutionary psychology based dodecabond model (as shown adjacent).
 A equation overlay depiction of an strong A≡B type human chemical bond actuating between two people (human molecules) newly in love during war times.

Long-term stable marriages are held together via the Gottman stability ratio. In the basic attachment reaction, between two unacquainted individuals, A and B, a collision will occur, in a time-accelerated sense, and the resultant "bond" that form can have various degrees of attachment strength:

A + B → AB (very strong bond)
A + B → A≡B (strong bond)
A + B → A=B (intermediate bond)
A + B → A-B (weak bond)
A + B → A--B (weaker bond)
A + B → A - - - B (detaching stage bond)

The question then immediately becomes: "how are these human chemical bonding variations (A≡B, A=B, A-B) quantified?" The central answer to this question lies in the understanding of the photon-electron interactions of the outer valence shell electons of the bonded individuals, as is the case with all attachments between molecules.

In this direction, human chemical bonds can be studied and modeled from a number of perspectives, such as an "orbital perspective", i.e. tracking the spatial movements of attached people over time on the surface of the earth, an "exchange force" perspective, in which an exchange of particles, which accompanies the interaction and transmits the force, operates, from a "quantum mechanical" perspective, in which quantum inputs or outputs of energy cause jumps in hierarchy location, or from a psychological perspective, e.g. John Bowlby's attachment theory (1953) or Lewis-Amini-Lannon limbic bonding theory (2000), among other points of view, such as neurochemical operation, etc. This basic structure of the human chemical bond, using a male-female perspective, is diagrammed in simple form below, from an energy view perspective: [2]

History
See main: History of chemical bonding theory
The first to outline the logic of thermodynamic stability of bonding, in the context of free energy changes, it seems, was American physical chemist Gilbert Lewis in 1916. [7] The earliest views on human bonding can be traced to the early 20th century work of various parent-child psychologists, such as Anna Freud, Melanie Kline, James and Joycle Robertson, John Bowlby, Mary Ainsworth, Marshall Klaus, and John Kennell, among others, who developed theories on "attachment" and "parent-infant bonding". [3] Views on the neurochemical operation of the human bond, popularizing conceptions such as that oxytocin is the "cuddle chemical", began to emerge after the year 1954, the founding year of the discipline of neurochemistry. [5]

Goethe
In 1809, Johann Goethe was conceptually modelling human relationships via William Cullen chemical bonding brackets, according to which the crotchet "{" was conceptualized by Goethe, based on his reading of Bergman (1775), as the chemical force of the union, or something along these lines; which is diagrammed as follows:

The following is an example synopsis quote:

“At the heart of Elective Affinities lies the conversation on chemistry about the elective affinities of inorganic substances. Various experiments with calcium have proven that affinities between certain substances are stronger than those between others, that in fact the introduction of a new substance to a chemical compound will cause an existing chemical bond to be broken and a new composite to be formed. Goethe takes this observation about chemical substances, and applies it to a number of carefully selected people [humans] in a great variety of circumstances and combinations. The novel then traces the effects of this ever-changing pattern on individuals, showing which affinities crystallize out as the strongest.”
Gundula Sharman (2002), Twentieth-century Reworkings of German Literature (pg. 156)

Granovetter
In 1969, Mark Granovetter, in his “The Strength of the Weak Ties”, based on the hydrogen bonding models he had learned in chemistry class, outlined a "weak tie" and "strong tie" mode of human associations, as illustrated as below, wherein strong ties are akin to covalent bonds, and weak ties are akin to hydrogen bonds:

Beg
In 1987, Mirza Beg, in his New Dimensions in Sociology (pgs. 72-74), was using implicit human chemical bonding models; for example in the following equilibrium reaction between close friends, A and B:

A + B $\rightleftharpoons \,$ AB

He was referring to what he termed the "A-B linkage", how a "linkage is established between the two persons", and in three potential "dimer-formering" reactions, where AB is the dimer, according to Beg, he gave three possible reactions between human species A, B, and C, as follows:

A + B $\rightleftharpoons \,$ AB

A + C $\rightleftharpoons \,$ AC

B + C $\rightleftharpoons \,$ BC

He speaks of "weak linkages" as compared to "strong linkages" in the above three scenarios. Beg did not, however, explicitly digressing on HCB theory.

Mimkes
In 2002, Jurgen Mimkes, in his "Chemistry of the Social Bond", was suggesting that social bonds were chemical bonds and a function of internal energy and or free energy; and in the 2002 CFI SocioPhysics Conference was lecturing on this; the abstract of which is as follows: [9]

“The state of large stochastic systems of N objects may be calculated by the Lagrange principle L(N) = T log P(N) + E(N) → maximum ! P is the probability, that is to be maximized under a system condition E, and T is the Lagrange ordering parameter. L is the Lagrange function of the system, that may be far away or close to stability. At equilibrium the Lagrange function is at maximum. In natural sciences E is given by the chemical bonds and the (negative) Lagrange function corresponds to the free energy, from which all thermodynamic states may be calculated. In social systems the Lagrange principle corresponds to the common benefit. The function E represents the social bonds of the system.”

Thims
In c. 2003, Libb Thims began to grapple with the human bonding, viewed such that the human bond is a chemical bond, such as described by American chemical engineer Linus Pauling's 1931 article "The Nature of the Chemical Bond", when it became apparent that part of human free energy, such as active in a human reproduction reaction, are contained in the marriage bond of the parental structure. Thims, in short, between the years 2001 and 2007 grappled with theory behind the bond, as briefly outlined in the 2005 unfinished article "On the Nature of the Human Chemical Bond". [4]

 A 2004 field particle exchange model of the human chemical bond, according to Libb Thims.
In late 2001 and early 2002, Thims had originally conceived of the basic human reproduction as: A + B C, in which A and B are the reactants (the dating pair) and C is the product (a 15-year old child). In this mode of logic, Thims had no conception of a the "AB attachment" or bond (this detail was ignored in early calculations). In late 2002 or early 2003, however, it became apparent to Thims that he was leaving out an important component of the reaction, i.e. the AB bond of the attached couple or married pair in the standard initial state and end state of the standard 18-year reproduction reaction:

AB + CD A≡C + BD

where, in this reaction, AC are the male A and his sperm B, CD is the female C and her egg D, at the second of love at first sight, A≡C is the bonded in marriage parental structure, and BD is the 15-year old child precipitate of the reaction beginning to detach from the parental structure to go off into the world as a newly synthesized individual unattached human molecule.

The investigation then began to understand what this “AB bond” means from a chemical point of view or fundamental forces point of view. For at least a half a year or more, the issue remained a puzzle. On November 10, 2003, Thims synthesized the concept of 'human molecular orbital theory' as based on 'hybridized molecular orbital theory' of small molecules according to the Schrodinger equation. On May 05, 2004, Thims formulated a 'field particle exchange theory' of human bonding as based on QED, QCD, particle physics, evolutionary psychology, and particle physics, which defines human molecules to be attached via the exchange of field particles.

On the Nature of the Human Chemical Bond

In 2005, Thims made an attempt at writing a journal article entitled "On the Nature of the Human Chemical Bond", but left the article unfinished after nearing the thirty page mark, and realizing the subject would not fit on single webpage. [4] Nearing the end of 2005, it became apparent to that in order to discuss the nature of the human chemical bond in the correct light, he would have to write up a complete textbook on “human chemistry”. Subsequently, he spent the next 18-months and 14-days doing so. The 824-page, two-volume bookset Human Chemistry was published in September of 2007. Of which nearly half of the book is devoted to the explication of the human chemical bond.

Quotes
The following are related quotes:

“While Prigogine’s attention here is on chemical and biological phenomena, his concern is equally relevant to the operation of societies. While we may imagine the bonding and coupling of chemical elements through electromagnetic attraction or the basic force that holds the nucleus of atoms together, we daily experience and contend with the forces and attractions that seem to hold people in social relations. We can feel in our viscera and conceptualize in our mental models the ‘reason’ that we hold onto a job or divorce a spouse. The bonds and forces of society are utterly different from those of atomic or chemical reactions, but the fact in common is that complex things must be constructed and that it costs energy to bring this about.”
Richard Adams (1988), The Eighth Day (pg. 75)

 The standard human chemical thermodynamic "dodecabond model" (2007) of human chemical bonding, defining attachment between two humans in terms of enthalpic ties and entropy ties, shown in the context of a human molecular orbital view. [1][3]
References
1. Thims, Libb. (2007). Human Chemistry (Volume Two), (preview), (ch 13: "Human Chemical Bonding", pgs. 515-560). Morrisville, NC: LuLu.
2. The "energy-view perspective" is modeled on the energy-view perspective of sub-atomic relationships, such as in the structure of a proton or neutron, in which approximately 90% of the mass of the structure is found in the gluon bonds. In the structure of any nucleon, according to Dutch theoretical physicist Martinus Veltman, winner of the 1999 Nobel Prize in physics for in 1999 "for elucidating the quantum structure of electroweak interactions in physics", from his 2003 book Facts and Mysteries in Elementary Particle Physics, most of the mass or "energy", as these are equivalent via Einstein's mass-energy equivalence relation, of sub-atomic particles actually resides within the bonds. In the proton, for instance, which consists of two up quarks and one down quark each connected together via gluon "gab" bonds, 923 MeV of its total mass (938 MeV) resides within the gluon bond. Hence, in colloquial terms, most of the essence of the proton or quark relationship is actually found within the bond.
3. Thims, Libb. (2007). Human Chemistry (Volume Two), (preview), (ch 12: "Bond History and Neurochemistry", pgs. 469-513). Morrisville, NC: LuLu.
4. Thims, Libb. (2005). “On the Nature of the Human Chemical Bond.” Journal of Human Thermodynamics, Vol. 1, Issue 5 (pg. 36-61) – November (left un-finished).
5. Neurochemistry (the science of the chemistry of the nervous system) traces it origin to a series of International Neurochemical Symposia, of which the first symposium volume published in 1954 was titled "Biochemistry of the Developing Nervous System" (source: Basic Neurochemistry, 7th ed, 2006).
6. Forman-Kay, Julie D. (1999). “The ‘Dynamics’ in the Thermodynamics of Binding.” Nature Structure Biology, 6: 1086-87.
7. Lewis, Gilbert. (1916). “The Atom and the Molecule”, Journal of the American Chemical Society, Vol. 38, Jan. pgs. 762-86.
8. Mesny, Mary B. (1910). “Human Molecules”, The Smart Set: a Magazine of Cleverness, 31:100, May.
9. (a) Mimkes, Jurgen. (c.2002). “Chemistry of the Social Bond” (“Chemie der sozialen Bindungen”) (pdf) (Eng), University of Paderborn.
(b) Mimkes, Jurgen. (2002). “The Structure of Complex Systems: Thermodynamics, Socio-Economics”, SocioPhysics Conference (abs) (toc) (pdf), Center for Interdisciplinary Research (Zentrum fiir interdisziplinare Forschung) (ZIF), Bielefeld Germany, Jun 6-9.