I did not want to do a blog about resumes...but as a career coach with a background in HR, Organizational Development, and recruiting, I felt obligated to my clientele to "weigh-in" and provide insights that can benefit them on this subject.
Because this is a boring topic devoid of any sex appeal or real psychological basis, I must be succinct, if not pointed. This is the truth about resumes:
They don't matter as much as you think they do, and they also matter more than they should.
Resumes are footnotes to your work history. History is boring - significant - but boring (not as boring as the topic of resumes though). Your past - like everything else on your resume - only matters to the degree that it demonstrates your ability to do the job you are applying for. Period.
This is (slightly) where the psychology comes in (it's also where things fall apart for the majority of those who write and submit resumes). Most people (out of the need for self-verification) can't fight the compulsion to pour every detail of their work lives into their resumes - which get discounted or discarded as a result.
This is when resumes matter more than they should. Good candidates never get into the ring because their resumes don't get them invited - which is what your focused and highly relevant resume is supposed to do.
But most resumes don't get read. They get skimmed (or scanned). Working with HR at large companies, I can attest: The hiring process is a disruptive/painful process that most companies just want to get through. They are often more concerned with merely filling the position than with finding the right person. But if you connect with them (through personality, similarity, and/or the proper articulation of your personal value proposition to do the job) the resume becomes secondary, and the focal point of the job interview is whether they can see themselves working with you (i.e., if you "fit in").
This is when resumes don't matter as much as you think they do.
Bottom line: Resumes are a necessary evil. When the time comes to create and submit one, it's imperative that you focus on the needs of the employer, and showcase your personal value proposition in that context, on your resume, and during your interview.