I don't think anyone has said that teaching kindergarten or phys ed requires superior intelligence, but do not assume that those who choose to teach do not possess superior intelligence. You would be surprised how many of those teacher's have quite a bit of post-baccalaureate training/schooling and could easily have pursued a career in medicine, but chose not to. Not everyone's career calling is based on their IQ. Believe it or not, some of us actually had other jobs before we became teachers that required quite a bit of the superior intelligence you speak of.
I beg to differ that children learned better during the days of a one-room school house. This assumes that the world we live in today is exactly the same as the one that existed then. The two cannot be compared in any way, shape, or form. The most glaring difference is that the curriculum requirements today are much more stringent. Teachers who taught in a one-room school, rarely were teaching algebra and geometry concepts to 2nd & 3rd graders. They taught the basics of arithmetic, not mathematics. English was spelling and basic sentence construction, not research papers in the 5th grade. Few children learned to read beyond a 6th grade level.
There was cooperation between school and home. Homework was a priority, something students did on their own and parents didn't complain if they got "too" much. There were fewer disruptive students, heck there were fewer students period. The teacher had built-in assistants; the older students often tutored the younger ones. When a student was disruptive, the teacher was permitted to use corporal punishment and the parent followed up at home with more of the same instead of blaming the mean teacher.
both my children attend and have attended in 'one room school houses' for years-and based on their experiences and the experiences of multitudes of other students who have been taught within the same system they are learning better.
in actuality the children for the bulk of lessons are taught in 2 separate classrooms (k or 1st-3rd and 3rd or 4th -8th). our curriculum meets and exceeds the most stringent requirements in the public schools and the lower grades are routinely learning algebra and geometry. language instruction includes continuing teaching concepts into upper grades that with regularity abandoned in traditional schools at 3rd grade level (which may be the reason the students in later years achieve well above national norms in college testing), and research papers are introduced well before 5th grade (dd was doing them in 3rd, ds in rudimentary form in 2nd). one of the clear advantages of a multi grade classroom is that younger students are exposed to material and concepts that will come up later in their education-giving them an advance look at 'the next step', which we've found they often have greater success in learning and applying by virtue of this exposure. older students by virtue of being in the classroom with younger students are exposed to reinforcement of basic skills and historical concepts that are the basis for their current learning which strengthens their abilities.
my kid's teachers (there are 2, no aides, no older students teaching the younger students) are both college educated and meet or exceed our state's credentialing requirement. there is no homework-not the school's policy unless a child fails to complete their own daily work. no corporal punishment. no more and in actuality less parental involvement than i've seen in most public schools (as an observer and former teacher)-and behavioural problems can be of much greater degree since the school system has traditionaly been a 'last hope/ditch' effort on the part of some parents whose kids have been refused traditional public education ('no tolerance' policies permitted districts to remove kids from public schools with proviso of private tutor, parents could'nt/would'nt quit jobs to stay at home all day to supervise kids).
reading 'levels' from past centuries cannont be compared with modern standards because while rural children did have a higher rate of completion/drop out at a younger age, the reading materials were vastly different (and in many cases before the popularity and availability of the mcguffey readers, the bible was used in even the youngest of grades) so what is now considered the level expectation for a 3rd grader was 'back then' in actuality what was being taught in younger grades (reading level expectations were lowered in the u.s. and the mcguffy's and other texts revised DOWN when large non native english speaking children became a larger population in public schools as a means to address the need for greater emphasis on basic english skills).
while i did not keep the materials from back when i went through college to support it, i would disagree that the more traditional historical one room school teacher had it easier or taught at a lower level of instruction. i recall reviewing curriculum guidelines and teacher testing criteria during a course i took on the history of education and the amount of material that those teachers taught was very impressive. while there was not the scope of mathmatics and scientific information that present teachers must cover, there was a much greater emphasis on history, geography, political science than most modern day elementary schools begin to cover (and let us not forget that those teachers also taught with regularity subjects that no current multiple subject/single grade teacher generaly ever covers in their regular curriculum-bible, full blown music instruction, formal public speaking and health).
as for a previous post about teachers back then just 'taking the test' to teach-'the test' in actuality was commonly either a multiple day written and oral test that determined a teacher's proficiency in ALL the subjects they would conceivably be held responsible for, or, a totaly oral exam in which proficiency was proven by oraly demonstrating knowledge in each of the subject matters (in history for example a teaching candidate could be required to give an entire oral history of the united states including pertinant names, dates and events-including their locations). as compared to modern day credentialing tests which largly test on educational theory these tests were much greater in subject comprehension.
i think before anyone starts placing current teaching standards/methods over those of the past they should first consider that it was that form of education that produced the individuals that invented and created the base forms of the mechanisms, technologies and advancements that we take for granted today as 'simplistic' but without which our society and world would be in a very different place.
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but then i could'nt have been too dumb-when i applied to graduate under the MINIMUM criteria within my state's teaching program i had enough units to receive 4 separate degrees
I'm currently doing my practicum in a K class. I love it but it's exhausting! And I know it's the grade for me. But many of my peers say, NO WAY to K! 
