For most of human history, life expectancy was about 30 years.

Judge as of 2018-03-22. The claim is rough ('30') and is read as life expectancy at birth across most of human history (prehistoric and pre-modern periods). True: demographic and historical estimates put average life expectancy at birth for most of history at roughly 25–35 years. Mostly true: estimates average in a slightly wider band (about 20–40) centred near 30. Mixed: estimates vary so widely across periods that about 30 fits only roughly half of them. Mostly false: the figure is real only for a narrow period or population and is stated as general, or it describes something other than life expectancy at birth. False: estimates for most of history lie well outside 20–40.

Set before the research began.

1. E1 Demography of the Roman Empire - Wikipedia Wikipedia · 19 June 2010

   “Life expectancy at birth in the Roman Empire is estimated to have been about 22–33 years.”

2. E2 Life expectancy - Wikipedia Wikipedia · 9 January 2002

   “Human remains from the early Bronze Age indicate an LEB of 24.”

3. E3 Historical life expectancy in selected regions 33-1875 | Statista Statista · 31 December 2006

   “For most of the world, throughout most of human history, the average life expectancy from birth was around 24.”

4. E4 A Brief Overview of the Health Transition (Chapter 1) - Rising Life Expectancy Cambridge University Press · 5 February 2015

   “In some places and times before 1800 life expectancy at birth may have reached or even slightly surpassed forty years.”

The quoted estimates of life expectancy at birth before modern times range from about 22 to about 40 years [E1][E2][E3][E4]. They put the Roman Empire at about 22–33 years (E1), the early Bronze Age at 24 (E2), most of human history at around 24 (E3), and some places before 1800 at up to about 40 (E4). Several of these estimates are below 25 rather than centred on 30, so the figure fits the wider 20–40 band, not the 25–35 band needed for "true". This matches the criteria for mostly true.