I wonder where to put this quote...
“”Have I ever heard a sceptic wax superior and contemptuous? Certainly. I've even sometimes heard, to my retrospective dismay, that unpleasant tone in my own voice. There are human imperfections on both sides of this issue. [...] And, it must be said, some scientists and dedicated sceptics apply this tool [scientific scepticism] as a blunt instrument, with little finesse.
|—Carl Sagan, The Deamon-Haunted World, Chapter 17: The Marriage of Scepticism and Wonder|
Views on brain size and intelligence
Carl Sagan suggested that the advent of Caesarean sections and in vitro fertilization may permit humans to evolve larger heads, resulting in improvements via natural selection in the heritable component of human intelligence  However Wikipedia’s page for  says that neurological functions are determined more by the organization of the brain rather than the volume, Neanderthal cranial capacity for females was 1300 cm3 and 1600 cm3 for males,  while among modern Homo Sapiens, northern populations have a 20% larger visual cortex than those in the southern latitude populations, and this potentially explains the population differences in brain size (and roughly cranial capacity).  
- Sagan, Carl (1977). The Dragons of Eden. Random House.
- Stanford, C., Allen, J.S., Anton, S.C., Lovell, N.C. (2009). Biological Anthropology: the Natural History of Humankind. Toronto: Pearson Canada. p. 301
- "BBC News - Dark winters 'led to bigger human brains and eyeballs'". BBC News.
- Alok Jha. "People at darker, higher latitudes evolved bigger eyes and brains". the Guardian.
Just in case it gets clobbered by a later edit:
Baloney Detection Kit
In the "Fine Art of Baloney Detection" chapter of Demon Hunted World provides a method for doing science and spotting pseudoscience. This is an abridgment of the full kit not the partial versions that may people point to.
- How reliable is the source of the claim?
- Does this source often make similar claims?
- Have the claims been verified by another source?
- How does the claim fit with what we know about how the world works?
- Has anyone gone out of the way to disprove the claim, or has only supportive evidence been sought?
- Does the preponderance of evidence point to the claimant's conclusion or to a different one?
- Is the claimant employing the accepted rules of reason and tools of research, or have these been abandoned in favor of others that lead to the desired conclusion?
- Is the claimant providing an explanation for the observed phenomena or merely denying the existing explanation?
- If the claimant proffers a new explanation, does it account for as many phenomena as the old explanation did?
- Do the claimant's personal beliefs and biases drive the conclusions, or vice versa?
- Ad hominem
- Argument from authority
- Argument from adverse consequences
- Appeal to ignorance - the claim that whatever has not been proved false must be true, and vice versa
- Special pleading
- Begging the question, also called assuming the answer
- Observational selection, also called the enumeration of favourable circumstances, or as the philosopher Francis Bacon described it, "counting the hits and forgetting the misses*
- Statistics of small numbers
- Misunderstanding of the nature of statistics
- Non sequitur - Latin for 'it doesn't follow'
- Post hoc, ergo propter hoc - Latin for 'it happened after, so it was caused by'
- Meaningless question
- Excluded middle, or false dichotomy
- Short-term v. long-term
- Slippery slope, related to excluded middle
- Confusion of correlation and causation
- Straw man
- Suppressed evidence, or half-truths
- Weasel words