Rules and Words - solution

Below the break is the solution and notes for Rules and Words.

Answer pairs with the definitions in their clues exchanged are taken from the titles of books by Steven Pinker: The BLANK SLATE, The SENSE of STYLE, The LANGUAGE INSTINCT and The BETTER ANGELS of Our Nature.

Across

7 Traditions in this place including one identifying mark (8) HERITAGE
1+TAG in HERE

8 Heavily criticize store carrying loss-leader (5) BLANK (def. for SLATE)
L(oss) in BANK

10 Envelopes afford letter openers breaking into sealed wax circle? (8) TEALIGHT
first letters of 'Envelopes Affod Letter' inside TIGHT

11 Five-point type (5) SENSE (def. for STYLE)
ie, five compass points

12 Young team leader employed by Lakeland (5) AKELA
hidden in 'Lakeland'

13 Be like a son leaving flock again (8) RESEMBLE
REASSEMBLE with A S(on) leaving

15 Perhaps Seagal movie's screening time (6) STEVEN
SEVEN (a movie) around T

16 More left-wing writing, according to jackets (6) PINKER
INK inside PER

18 Get clip from director till actors wrap (8) TORTILLA
hidden in 'direcTOR TILL Actors'

21 Drug punishment (5) SMACK
two definitions

23 Pen an article in French judgement (5) STYLE (def. for SENSE)
STY + LE

25 A pointer to follow? (5,3) GUIDE DOG
GUIDE (a pointer) + DOG (to follow), whole clue gives possible definition

26 Doctor left seat vacant (5) SLATE (def. for BLANK)
anagram of L SEAT

27 One beginning to detect a certain something in girl's plainness (8) LUCIDITY
1 + D(etect) + IT in LUCY

Down

1 Agree arrangement when adopting new parts of a family (6) GENERA
anagram of AGREE with N inside

2 Jumping or throwing things to let off steam after I'd feel upset (5,5) FIELD EVENT
VENT after anagram of 'I'd feel'

3 Basic capacity from network meter showing a partial upturn (8) LANGUAGE (def. for INSTINCT)
LAN + GAUGE with two letters reversed

4 Business leader replaces first item in memo for investors (6) BETTER (def. for ANGELS)
B(usiness) replacing first letter of LETTER
5 Puts down a guitar after covering Eagles' No 1 (6) ABASES
A + E(agles) in BASS

6 It helps to remember Violet's big-headed (4) VAIN
reference to mnemonic for colours of rainbow "Richard of York..."

9 I'm praying woman in political scandal takes top spot in newspapers (7) KNEELER
(Christine) KEELER with N inside

14 Patch up net before afternoon starts? (4,6) MAKE AMENDS
MAKE + A.M. ENDS

15 Partners from post office function on board (7) SPOUSES
PO USE inside SS (ie 'on board' a ship)

17 Tintin's comics originally translated into English maybe (8) INSTINCT (def. for LANGUAGE)
anagram of TINTINS C(omics)

19 Ogled ginger man first (6) LEERED
RED with LEE first

20 Switching sides causes annoyance, I'll wager (6) ANGELS (def. for BETTER)
ANGERS with R (right) changed to L (left)

22 Difficult excerpt from book not typeset (6) KNOTTY
hidden in 'booK NOT TYpeset'

24 Yeovil and Arsenal in top two places for several seasons (4) YEAR
first two letters of Yeovil and Arsenal