The Half-Elven Point of View

Half-elves, the children of human-elf unions, are not in themselves a true race. Such individuals are found throughout human and elven societies, though not in any great numbers. In appearance half-elves, male and female, tend to stand apart from their contemporaries of either race. They are larger than elves and smaller than humans, with the coordination and mental sharpness of the former and the physical might and toughness of the latter. Their facial features (ears in particular) tend to carry a strong elvish influence, though hair color, skin color and texture, and eye color are largely derived from the human parent.
Despite these differences, most half-elves see themselves as gifted and not "strange." They are proud of their heritage and their abilities, and are widely accepted in most societies. If there were ever people who could make a claim to having the best of two worlds, half-elves would be the ones.
Even the inner nature of the half-elves shows a confluence of human and elven elements. A strong love of natural beauty and the outdoors is usually picked up from the elven parent, along with a strong hint of chaotic variability. Whereas elves are by comparison rather clannish and avoid contact with non-elven races, half-elves are very outgoing and make friends easily, perhaps a result of mixing the affinity elves feel for all living creatures with the adaptability of humans.
Half-elves appear very versatile, and manage to fit into a fairly wide range of social environments. They have a wider range of possible character classes and class combinations than any other race or being. Because they possess souls, half-elves may become normal clerics and druids; although the former class offers a rather limited career, as druids half-elves may achieve great power and influence. It would appear that half-elves have not as much capability for (or love of) magic as either humans or elves have, but they may reach reasonable levels of skill nonetheless. Their druid-like abilities also help make half-elves good at operating in the ranger and bard classes.
The most profitable career that some half-elves may turn to is, of course, thieving, in which they are marginally better overall than even humans. Half-elves seem to be exceptionally good at picking pockets; some believe this is because they present such a friendly appearance that people don't mind having them near, and some say it is a function of their exceptional curiosity. Evil half-elves make very good assassins, being able to pass through elven or human society and disguise themselves as members of either race. Only humans and half-orcs have enough taste for such a career so as to do better at assassin-style killing than half-elves.
Though long-lived, half-elves are not extraordinarily so. They tend to share the faster-paced human view of time than the all-the-time-in-the-world elven view. Still, with an average lifespan of 250 years, they tend to feel that they need not rush to do most things. They do seem to try to keep fairly active, and many half-elves are drawn to a vagabond, adventuring sort of life. Perhaps many of them feel some degree of separateness from the lives of humans and elves, not completely at home in either case even if otherwise welcome. Individually, half-elves are quite varied in personality. Some have more elven traits than human and others vice versa. A few manage to achieve a reasonable balance between the two ways of seeing things, mixing a deep respect for nature and life with the generally human desire to build and alter the environment, and interact with other peoples on a more frequent basis.
In religious matters, half-elves may adopt either human or elven deities; there doesn't seem to be any particular preference in either direction, though the society in which the half-elf was raised is usually the determining factor.
Most people think of half-elves only in terms of those who are the first-generation descendants of humans and elves; yet, such half-elves are fertile, and may have children by other humans, elves, or half-elves. Second-generation and further descendants will possess more of the characteristics of whichever bloodline is predominant. It is not unusual for otherwise normal humans on rare occasion to have infravision out to a range of several tens of feet, or pointed ears, or a light build, to remind them of an elven ancestor; in a similar manner, there are elves who may be stronger than normal, or have reduced resistance to sleep and charm spells, or a broader build, passed on by a human ancestor. It might have been more appropriate in the AD&D rules for half-elves to have had such variable qualities, to better reflect the unpredictability of genetics and heredity.
It is interesting to note that humans are apparently not the only beings that elves can intermix with. Tallfellow halflings bear distinct resemblances to their elven neighbors, for good reason. Since halflings are closely related to humans in many respects, this is not surprising. Half-elves of other racial mixtures are virtually unknown. Elves and orcs cannot interbreed, which is interesting since both races can breed with humanity.

The Half-Elven Point of View by Roger E. moore, Dragon Magazine #60, April 1982