the stuff the holds all the rest up or provides it with support ???

'Supports' is a current buzz word in the US, referring to those additional strategies and techniques that K-12 teachers employ in order to 'differentiate instruction.'

I think Robert's point about social support systems is quite valid.

I hope this helps, Neil.

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Note added at 6 hrs (2018-02-18 18:20:13 GMT)
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A question commonly asked by U.S. school administrators in the context of a struggling student is 'What supports have you provided?' (precisely like this in the plural form).

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Note added at 1 day 1 hr (2018-02-19 13:24:04 GMT)
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As far as 'scaffolding' goes, which personally I first heard of back int 90s (so it's not exactly a new term, it's the more techinical, high-register word for what many teachers nowadays at the K-12 level, at least in the United States, often refer to as 'supports.'

That said, given the register of the source text, 'scaffolding' may produce the closest 'equivalent effect.' I've just offered this an alternative in light of the asker's initial comments.