Human Design Variables

What the Variable is

In a Human Design chart, four small arrows sit beside the Head center, two on each side. Together they are called the Variable, and Human Design teaches them as the most detailed layer of the chart, the one said to describe not what you are but how you are built to live it. The two on the left come from the Design, the unconscious side drawn in red, and are read as the body: Determination, also called Dietary Regimen, how you are designed to eat and digest, and Environment, the kind of place where you do best. The two on the right come from the Personality, the conscious side, drawn in black on most charts and light on this site's, and are read as the mind: Motivation, what drives your thinking, and Perspective, how you are designed to see. In Human Design's own teaching, the left pair belongs to its health program, the Primary Health System, and the right pair to its psychology, Rave Psychology.

How the arrows are calculated

Every activation in a chart falls in one of the 64 gates and one of its six lines, and the line divides further. Each line, 56′15″ of the zodiac, holds six colors of 9′22.5″ each; each color holds six tones of 1′33.75″; and each tone holds five bases. The Variable reads the color and tone of four activations: the Design Sun for Determination, the Design North Node for Environment, the conscious Sun for Motivation and the conscious North Node for Perspective. The Earth and the South Node stand exactly opposite the Sun and the North Node, 32 gates away, so they always share their color and tone. The color, one of six, gives each arrow its type. The tone gives its direction: tones 1 to 3 point the arrow left, and tones 4 to 6 point it right.

Left and right

Human Design reads the direction of an arrow as the way that part of you works best. A left arrow is read as active, strategic and focused: it engages directly, zeroes in on specifics and does well with structure and routine. A right arrow is read as passive, receptive and open to the periphery: it takes things in broadly, holds them without aiming, and needs less structure. Each arrow has its own names for the two directions. Determination points left for Active and right for Passive; Environment left for Observed and right for Observer; Motivation left for Strategic and right for Receptive; and Perspective left for Focused and right for Peripheral.

How exact the birth time must be

The Variable is the most time-sensitive part of the chart. The Sun moves about a degree a day, so it crosses a tone in about 38 minutes, and its two arrows, Determination and Motivation, turn about every 1.9 hours and change color about every 3.8 hours: over a single day the Sun passes through all six colors, both ways. The North Node moves far more slowly, so Environment and Perspective turn about every 31 hours on average and change color about every two and a half days. Without a birth time, then, the Sun arrows cannot be read at all, and each Node arrow is certain on only about half of birth dates. With a time, the calculator gives the span of birth times over which all four hold.

Why the two top arrows are linked

The Design Sun always stands exactly 88° behind the conscious Sun, and 88° is a fixed number of colors and tones, so the two Sun arrows are tied together. Your Determination color is always either the same number as your Motivation color or one higher, counting on from 6 back to 1: one higher in 80% of charts and the same in 20%. A Fear Motivation (color 1), for example, comes with a Taste or an Appetite Determination and never with the other four. The two arrows also point the same way in 60% of charts rather than half. The Node arrows have no such tie, because the node moves a different distance in the three months between the two moments.

Finding your Variable

The free Human Design chart draws the four arrows beside your Head center and names each one's color and direction, with the span of birth times they hold for; without a birth time, it shows only the arrows your birth date settles. The sections below give every color of every arrow and how common each direction is. Some teachers add that the environment matters most from the Saturn return, around the age of 29. Like the rest of Human Design, the Variable is a framework for reflection rather than established science, and the tradition itself presents it as advanced material, to explore once you know your type, strategy and authority.