Claim
The next generation of eyebrows will evolve to be hairier, bolder, and more unruly, following the trend of millennia past.
Evidence
For centuries, eyebrows have been completely shaved, mercilessly plucked, painted on, and experimented with. Brows on women have not only been a key feature in beauty trends, but they also aid specifically in facial recognition. Though the trends of different eyebrow arches, lengths, thicknesses, and definition seem to vary drastically between the decades, there is a clear progression towards one style. In the Victorian and Middle Ages, it was popular for women to completely rid themselves of all facial hair, including their eyebrows. This time period marks the beginning of conscious brow styling. From there, in the 1920s-30s, brows were heavily plucked, and even painted on, to reveal thin arched lines to accentuate the brow bone and highlight facial expressions. In the next generation, it suddenly became popular to leave eyebrows without tweezing because the unibrow became the desired look. By the mid-60s, the unruly excess hair was trimmed, still leaving an very bushy and natural brow shape. Since then, we have defined the arch point and tamed stray hairs to achieve a full, bold, and "instagram-esque" look. These variations in brow style clearly follow a pattern of common styles and trends of the time.
Reasoning
The above evidence highlights the winding history of eyebrows in style, and it clearly shows a progression from thin and nearly non-existent brows to full, bold, and more natural features. Trends mark what is a desirable trait during a given period of tine, whether this be a certain body type, hair color, boot length, or eyebrow characteristic. Evidence points to the fact that trends at a point in time will correspond with each other. For example, fashion in 2017 seems to jump back to the 80s and 90s, with items such as denim jackets, loose-fitting jeans, wide-rimmed glasses, and hair scrunchies. Therefore, the current trend for eyebrows will likely transform into styles that were popular in the 80s and 90s. Even though the enviable eyebrow identifies as bold, filled-in, and defined edges for the time being, the future will likely bring a bushy and dramatic throwback brow - a tribute to the current beauty trends in other fields.
Rebuttal
Because the current style is the instagram look - bold, defined, and penciled-in -, many believe that the future brow will be increasingly defined and may revert back to the thin style from the 1920s. However, current throwbacks in the fashion industry point to the 1980s-90s. It is very unlikely that women will be interested in sporting over-plucked eyebrows with a cute outfit, and it is even more unlikely that the future will hold a fashion throwback to the flapper era. Thus, it is proven that women will correspond their eyebrow style to their other beauty trends, matching a set of vintage clothes to a pair of natural brows.