The textbox on page 30 briefly outlines the ongoing academic controversy and debate as to how to interpret the development of hoplite fighting, and whether and to what extent it was connected to political changes happening in Greek cities in the same period. Why not read further on this topic? Recently, an entire book has been dedicated to this debate which contains papers by leading academics in both camps:
D. Kagan and G. Viggiano (eds), Men of Bronze: origins of the hoplite phalanx (Princeton UP 2013)
If you wish to trace the history of the academic debate, then you could read the following articles:
Antony Snodgrass, 'The hoplite reform and history’, JHS 85 (1965), 110-22 (a sceptic)
Paul Cartledge, 'Hoplites and heroes', JHS 97 (1977), 11-27 (an advocate)
John Salmon, 'Political hoplites?', JHS 97 (1977), 84-101 (a critic)
Hans van Wees, 'The development of the hoplite phalanx', in van Wees (ed.), War and Violence in Ancient Greece (CPW, 2000)
