People need to realize that pot is really two different strains (indica and sativa) with different effects depending on the blend and person.
acutally, that terminology/taxonomy is outdated. If you want to get into specifics, weed WAS actually classified into four distinct categories: sativa, indica, afghani, and ruderalis.
there is a problem with that terminology. first of all, different sativas have different chemical make ups and taxonomies. For example: south african sativas (e.g durban poison) have high levels of THCV and very little THC - a property that south american (e.g santa maria) and asian sativas (thai haze) do not have any or very little of. The different strains of sativa or indica are unique and inbred to the point that they could not be considered part of the same category. take for example Mazar, Kush, and afghani #1 - all are landraces from the indo-pakistani region. technically all indica or afghani, but all are different taxonomically, and all have very different effects and growing tolerances/requirements.
then theres the issue of modern breeding. 99.99% of weed on the market now is a cross between a sativa-like and indica-like plant. therefore, they are now neither and in a category of their own. "sativa dominant" or "indica dominant" means nothing because there are indica-looking strains with sativa effects and vice versa. there are in fact many, many categories of weed out there: skunk, white strains, diesel strains, kush strains, none of which can be categorized into one of the main types, but that are all a stable, unique strain by themselves.
how would you classify the Lowryder for example? it's a cross between an indica, ruderalis and sativa. it has sativa leaves and stem structure, indica buds, autoflowers like a ruderalis, and grows 2' max. it's a stable F1 strain. you cant classify it based on the effect or chemical makeup because it has elements of both, and you obviously cant classify it taxonomically. how then is it possible to only have two, or four distinct varieties of weed? there are many.
then there is the issue of harvest time and growing methods. depending on how you grow a plant and when you harvest it can create different effects. a simply waiting an extra week to harvest, or harvesting a week early can determine if the weed will have the so called "sativa-like effect" or "indica-like effect". How you dry it and cure it will also change the effect. take weed from the same plant, dry half in the closet and stick fresh buds in a jar for a few weeks, and dry the other half in the sun and dont cure it at all. you will have the same weed that gives you two distinct unique highs and the untrained eye will not be able to tell it came from the same plant.
so basically the logic behind the current fashion of categorizing weed as indica or sativa is flawed and misleading. weed is classified by the specific strain itself, growing methods, harvest timing and curing methods. Assuming they can be divided taxonomically into two to four types is just a propagation of the very conciousness you seek to expel by smoking weed - it's the assumption that just because someone told you or you read it in some book it means it's true. i dont care if jorge motherfuckin cervantes or mark emery tells me there are only four types, i refuse to believe that based on my own growing experience.